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Previous Lectures
- The Silent Guardians of the Grid: Unveiling Fault Current Limiters Shuki Wolfus (BIU)
Shuki Wolfus (BIU)

Power grids are the backbone of modern society, yet they remain vulnerable to sudden surges in current – fault currents – that can damage equipment and trigger blackouts. Fault current limiters (FCLs) act as silent guardians, automatically mitigating these surges and safeguarding grid stability. This talk will delve into the world of FCLs, exploring the state-of-the-art in both resistive and inductive, superconducting and non-superconducting, FCL technologies.

The unique work being done at Bar-Ilan to push the boundaries of FCL performance will be described. We will discuss novel FCL designs, and the potential for these innovations to revolutionize power grid resilience.

- Imaging quantum materials with scanning SQUID microscopy Beena Kalsiky (BIU)
Beena Kalsiky (BIU)

Competition or cooperation between different electronic orders with similar energy scales often gives rise to new or unexpected behaviors. Detecting traces of such orders requires versatile probes, which can probe different aspects of the system, such as conductivity, superconductivity and magnetism. In my talk, I will describe a few systems where our local view uncovered surprising mesoscopic effects. I will focus on two polymorphs of a van-der Waals material, 4Hb-TaS2, in which we found a hidden magnetic phase, revealed by spontaneous vortices hosted by the superconductor, and 1T- TaS2, a switchable charge-density-wave system in which we found a surprising rearrangement of current flow. Overall, our results highlight the power of scanning SQUID microscopy in probing the properties of quantum materials and providing local insights into their behavior.

- From interaction-free measurements to counterfactual communication Lev Vaidman (TAU)
Lev Vaidman (TAU)

A bomb explodes when anything interacts with it: Can it be found without exploding it? Can we find that the bomb is not present in a particular place without any probe being there? Which tasks can be achieved without particles in the transmission channel: transmission of a classical message, teleportation of a quantum state, establishing a secret key? I will review the claims that these tasks can be done and will argue that only some of them are true. 

- Friction, Earthquakes and Everything in Between Jay Fineberg (HUJI)
Jay Fineberg (HUJI)

Friction is generally described by a single degree of freedom, a ‘friction coefficient’. We experimentally study the space-time dynamics of the onset of frictional motion when two contacting bodies start to slide. We first show that the transition from static to dynamic sliding is governed by rupture fronts (essentially earthquakes) that break the contacts along the interface separating the two bodies. Moreover, we show that the structure and dynamics of these ‘laboratory earthquakes’ is quantitatively described by singular solutions originally derived to describe the motion of rapid cracks under applied shear. We demonstrate that this framework essentially replaces the idea of a ‘friction coefficient’ as a description for the onset of frictional motion. Moreover, this framework quantitatively describes both ‘laboratory earthquake’ motion and arrest. The results establish a new (and fruitful) paradigm for describing friction and provide a fundamental understanding of how earthquakes develop, progress and eventually arrest.

- Terrestrial and Astrophysical Probes of Dark Matter Tomer Volansky (TAU)
Tomer Volansky (TAU)

The existence of dark matter has been well established with overwhelming evidence, but its particle identity remains unknown. Significant progress has been made in recent years in expanding the dark matter search to new uncharted territories. In this talk I will focus on the possibilities to probe dark matter terrestrially as well as indirectly, focusing, in part, on light and ultralight dark matter, which have been argued to be particularly motivated. I will briefly review the current status of the field and discuss new avenues in the search for dark matter.

- Galileo and the Science Deniers Mario Livio
Mario Livio

Galileo Galilei is one of those larger-than-life heroes of our intellectual history. There aren’t many scientists, after all, whose lives and achievements inspired plays (such as Brecht’s Life of Galileo), scores of poems, or an opera (by Philip Glass). For Albert Einstein, Galileo was “the father of modern physics—indeed, of modern science altogether.”

I will trace Galileo’s fascinating life as I will examine his monumental achievements in astronomy, mechanics, and the development of the scientific method. I will also analyze his complex and tragic interaction with the Catholic Church, which had eventually led to Galileo being denounced a suspected heretic by the Inquisition.

I will emphasize Galileo’s relevance to a world in which anti-science attitudes have proliferated, and where there is a widening schism between the humanities and the sciences. Galileo’s life serves as a potent reminder of the importance of freedom of thought.

- Chaos along renormalization group flows Shira Chapman (BGU)
Shira Chapman (BGU)

Renormalization group (RG) flows determine how the physics of a system depends on the length scale in which it is being probed. This is a fundamental concept in our understanding of any physical system. I will study how quantum chaos develops across different length scales in the Sachdev-Ye-Kitaev (SYK) model - a model of fermions with random couplings.  The model is special in that it is strongly coupled, chaotic and yet exactly solvable in certain limits.  The SYK model has gained significant interest in the past few years, both in the condensed matter community where it is proposed for modeling strange metal behavior and in high energy physics where it is proposed as a model for quantum gravity. I will explain how chaos develops across different length scales in the model. Time permitting, I will explain the relation of these results to black holes and quantum gravity.

- Coupling single electrons spins to a superconducting flux qubit Michael Stern (BIU)
Michael Stern (BIU)

The realization of a quantum computer represents a tremendous scientific and technological challenge due to the extreme fragility of quantum information. The physical support of information, namely the quantum bit or qubit, must at the same time be strongly coupled to other qubits by gates to compute information, and well decoupled from its environment to keep its quantum behavior.  

An interesting physical system for realizing such qubits are magnetic impurities in semiconductors, such as bismuth spins in silicon. Indeed, spins in semiconductors can reach extremely long coherence times - of the order of seconds. Yet it is extremely difficult to establish and control efficient gates between distant spins. Here we experimentally demonstrate a protocol where single spins can coherently transfer their quantum information to a superconducting device, which acts as a mediator or quantum bus. This superconducting device allows to connect distant spins on-demand without compromising their coherent behavior. 


[1] M. Stern et al., Phys. Rev. Lett. 113, 123601 (2014). 
[2] T. Douce et al., Phys. Rev. A, 92, 052335 (2015). 
[3] A. Bienfait et al., Nature Nanotechnology, 282,1038 (2015). 
[4] T. Chang et al., Phys. Rev. Appl., 18, 064062 (2022). 
[5] T. Chang et al., Phys. Rev. Appl., 19, 024066 (2023). 
- Photonic Time-Crystals Mordechai (Moti) Segev (Technion)
Mordechai (Moti) Segev (Technion)

Photonic Time-Crystals (PTCs) are media whose electromagnetic properties are modulated periodically in time. When the modulation period is comparable to a single cycle of the wave propagating within them, and the modulation amplitude is at least 10-20% of the refractive index, the dispersion relation in PTCs exhibits momentum bands separated by significant momentum gaps. The momentum gaps are especially interesting – as they give rise to exponential amplification (and de-amplification) of the waves associated with those gaps, extracting energy from the modulation (or giving away energy to it).  This talk will review the basic concepts of PTCs and will focus on light-matter interactions, especially on light emission in PTCs. The last part of the talk will describe recent experimental progress on observing time-refraction within a single optical cycle, and on nonlinear phenomena in these time-varying media.

- Catastrophic Failure in Defect-Sensitive Shells Shmuel Rubinstein (HUJI)
Shmuel Rubinstein (HUJI)

What is the force needed to crush a soda can? Surprisingly, there is no straightforward answer. From everyday items like soda cans to critical applications in aerospace engineering, accurately estimating the buckling loads for shell structures is crucial. However, these systems are extremely defect-dependent, and classical linear analysis frequently overestimates the buckling loads of cylindrical shells, leading to catastrophic failures. To address this challenge, we have developed a fully nonlinear framework inspired by research in turbulent flows. We tested this by smashing hundreds of commercial soda cans, such as Coke and Beer, and capturing the stability of shells through lateral probing to measure their stability landscape. Our results introduce a practical, fully nonlinear paradigm for understanding the fundamental processes that lead to catastrophic failure in shells.

- Statistical forensics of election fraud in Russia and other post-Soviet countries Sergey Shpilkin (Independent election researcher)
Sergey Shpilkin (Independent election researcher)

After a brief period of free and fair---if imperfect---elections in Russia in the 1990s, the 2000s saw a resurgence of Soviet-bloc practices in which the desired result is attained through purely administrative means up to and including direct falsifications. I will show how to reveal and quantify these falsifications by applying simple statistical tools to fine-grained election data. I will also present a couple of examples from other post-Soviet countries.

NOTE: The views and opinions expressed in this talk are those of the speaker and do not necessarily reflect the official policy or position of the university.

- Failed Theories of Superconductivity Joerg Schmalian (Karlsruhe)
Joerg Schmalian (Karlsruhe)
The microscopic theory of superconductivity was developed by John Bardeen, Leon N Cooper and J. Robert Schrieffer. It is among the most beautiful and outstanding achievements of modern scientific research. Almost half a century passed between the initial discovery of superconductivity by Kamerlingh Onnes and the theoretical explanation of the phenomenon. During the intervening years the brightest minds in theoretical physics tried and failed to develop a microscopic understanding of the effect. I will discuss some of those unsuccessful attempts to understand superconductivity. This not only demonstrates the extraordinary achievement made by formulating the BCS theory, but also illustrates that mistakes are a natural and healthy part of scientific discourse, and that inapplicable, even incorrect theories can turn out to be interesting and inspiring.
- Exposing hidden sectors Yotam Soreq (Technion)
Yotam Soreq (Technion)

Despite the huge success of the Standard Model of particle physics, it is not a complete description of Nature. It cannot account for several experimental results and observations and there are strong theoretical arguments that call for new physics. In this talk, we will discuss novel methods to hunt for new physics beyond the standard model at different energy and length scales, from atomic physics to future colliders.

- Black holes in binaries Ilya Mandel (MonashU)
Ilya Mandel (MonashU)

Recent observational successes are providing a new impetus to the study of binaries containing stellar-mass black holes.  I will start with a very brief review of the current understanding of massive binary evolution leading to the formation of black-hole binaries.  I will then focus on a few of the outstanding issues in interpreting both X-ray and gravitational-wave observations and propose pathways for improving our understanding of some challenging aspects of binary evolution.

- Inclusions, Boundaries, and Disorder in Active Matter Yariv Kafri (Technion)
Yariv Kafri (Technion)

Active systems are driven out of equilibrium by consuming energy and dissipating it into the environment. This endows them with anomalous mechanical properties, very different from equilibrium systems, that lead to rich physics when they interact with boundaries, bodies (inclusion), or disordered potentials. While on the one hand, active systems can propel, and rotate bodies placed in them, the bodies also have a non-trivial influence on active fluids. This is best exemplified by the propensity of bulk and boundary disorder to destroy phases in active matter, showing active systems to be much more sensitive to their surroundings than equilibrium ones. The colloquium aims at providing a unifying perspective on the rich interplay between active systems and their environments using the simplest class of active systems.

- Network GPS - Navigating network dynamics Baruch Barzel (BIU)
Baruch Barzel (BIU)
In the past two decades we made significant advances in mapping the structure of social, biological and technological networks. The challenge that remains is to translate everything we know about network structure into its actual observed dynamics. In essence, whether it's communicable diseases, genetic regulation, or the spread of failures in an infrastructure network, these dynamics boil down to the patterns of information spread in the network. It all begins with a local perturbation, such as a sudden disease outbreak or a local power failure, which then propagates to impact all other nodes. The challenge is that the resulting spatio-temporal propagation patterns are diverse and unpredictable - indeed, a zoo of spreading patterns - that seem to be only loosely connected to the network structure. We show that we can tame this zoo by exposing a systematic translation of network structural elements into their dynamic outcome, allowing us to navigate the network, and, most importantly, to expose a deep universality behind the seemingly diverse dynamics. Along the way, we predict how long it takes for viruses to spread between countries, which network components harvest most of the system's information, and how to resuscitate a collapsed network back into functionality.
- Simulation, control and sensing in open quantum systems Nir Bar-Gill (HUJI)
Nir Bar-Gill (HUJI)

The study of open quantum systems, quantum thermodynamics and quantum many-body spin physics in realistic solid-state systems, has been a long-standing goal in quantum and condensed-matter physics.

In this talk I will address these topics through the platform of nitrogen-vacancy (NV) spins in diamond, which have emerged over the past several years as well-controlled quantum systems, with promising applications ranging from quantum information science to magnetic sensing. I will first briefly introduce the NV center system, as well as the experimental methods used for measuring NVs and controlling their quantum spin dynamics. I will then detail our work in the context of bath characterization, purification (or cooling) of a spin bath as a quantum resource and for enhanced metrology and sensing.

I will describe our research on characterizing noise using robust techniques for quantum control ([1], in collaboration with Ra’am Uzdin). This approach suppresses sensitivity to coherent errors while enabling noise characterization, providing a useful tool for the study of complicated open quantum systems, with the potential for contributions to enhanced sensing. I will then present a general theoretical framework we developed for Hamiltonian engineering in an interacting spin system [2]. This framework is applied to the coupling of the spin ensemble to a spin bath, including both coherent and dissipative dynamics [3]. Using these tools I will present a scheme for efficient purification of the spin bath, surpassing the current state-of-the-art and providing a path toward applications in quantum technologies, such as enhanced MRI sensing.

Finally, if time permits, I will describe our work in using NV-based magnetic microscopy to implement quantum sensing in various modalities. I will present advanced techniques for improving sensing bandwidth using compressed sensing and machine learning. Demonstrations of NV sensing capabilities will include measurements of 2D vdW magnetic materials, and specifically the phase transition of FGT through local imaging of magnetic domains in flakes of varying thicknesses [4], as well as a technique for sensing radical concentrations through the change in the charge state of shallow NVs ([5], in collaboration with Uri Banin).


1.       P. Penshin et. al., in preparation.

2.       K.  I. O. Ben’Attar, D. Farfurnik and N. Bar-Gill, Phys. Rev. Research 2, 013061 (2020).

3.       K. I. O. Ben’Attar et. al., in preparation.

4.       G. Haim et. al., in preparation.

5.       Y. Ninio et. al., ACS Photonics 8, 7, 1917-1921 (2021).

- Unraveling the Mysteries of Tidal Disruption Events Assaf Horesh (HUJI)
Assaf Horesh (HUJI)

Tidal Disruption Events (TDEs) are cosmic occurrences where a star is torn apart by the immense gravitational forces of a supermassive black hole. This field is one of the key focus of contemporary astrophysical time-domain research, which offers critical insights into the nature of black holes, the dynamics of stellar destruction, and accretion physics. In my talk I will review our current understating of TDEs, and will address some challenges and pressing questions in the field. I will present new recent discoveries such as the (highly debated) association of neutrinos with TDEs, and my own discovery of delayed radio flares. The latter phenomenon shows that radio emission from TDEs can turn on sometimes months, and even years after stellar disruption. While we identified some possible explanations, the nature of these flares still remains mostly unknown. I will conclude by discussing future avenues in TDE research.

- Synthetic Ecology: Building Microbial Communities From The Bottom Up Jonathan Friedman (Hebrew U)
Jonathan Friedman (Hebrew U)

Ecosystems are arguably the most complex but least understood level of biological organization. Microbial communities, composed of numerous interacting species, are of particular importance as they play key roles in numerous application areas, including biotechnology, agriculture, and medicine. In this talk, I will discuss our efforts toward developing a predictive understanding of the structure and function of microbial communities. We found that a pairwise approximation of interspecific interactions is sufficient for predicting community structure in laboratory microbial communities. Furthermore, using high-throughput microfluidics, we show that interactions typically change qualitatively across environments, but can be predicted based on the growth abilities of individual species. These findings provide the first step toward “synthetic ecology”—the rational design and management of microbial communities.

- Physics can help make sense of immune system dynamics Herbert Levine (Northeastern University)
Herbert Levine (Northeastern University)

The task of understanding the dynamics of the immune system has been gaining increasing importance, as a consequence of progress in immunotherapy applied to cancer and due to the importance of vaccines, as with the COVID-19 pandemic. This talk will survey examples which show physics can help address some of the important conceptual and also practical issues that arise in this research area. Specific issues to be discussed includes the detection of neoantigens (immune-activating enzymes on the outside of a cancer cell) as a way to target tumor cells, the spatiotemporal dynamics of immune cell infiltration into tumors, the ecology of the immune microenvironment and the role of evasion by both cancer cells and evolving viruses.

- Earth’s Magnetic Field: Recent Discoveries from Archaeology and Its Use as a Dating Tool Erez Ben-Yosef (Tel Aviv(
Erez Ben-Yosef (Tel Aviv(

The geomagnetic field, one of the most enigmatic phenomena in Earth Sciences, is constantly changing. Our knowledge about it in periods prior to instrumental recording is based on geological and archaeological materials, the latter provide the highest resolution for the last 10,000 years. In this talk we will demonstrate how archaeology helps to better understand the geomagnetic field, including the discovery of the “Levantine Iron Age geomagnetic Anomaly” (LIAA), and how in turn our information on regional changes in the field helps to develop an efficient dating tool for archaeology.

Shlomo Havlin (BIU)

A theoretical framework for the percolation of interdependent networks will be presented. In interdependent networks, such as infrastructures, when nodes in one network fail, they cause dependent nodes in other networks to also fail. This may happen recursively and can lead to a cascade of failures and to a sudden fragmentation of the system. This is in contrast to a single network where the percolation transition due to failures is continuous.  I will present analytical solutions based on percolation theory, for the functional network and cascading failures, for a network of n interdependent networks. Our analytical results show that the percolation theory of a single network studied for over 80 years is just a limited case, n=1, of the general and a significantly richer case of n>1. I will also show that interdependent networks embedded in space are significantly more vulnerable and have significantly richer behavior compared to non-embedded networks. In particular, it will be shown that localized attacks of zero fraction but above a microscopic critical size lead to cascading failures that dynamically propagate like nucleation and yield an abrupt phase transition.  I will finally show that the abstract interdependent percolation theory and its novel behavior in networks of networks can be realized and proven in controlled experiments performed by Aviad Frydman on real physical systems.  I will present recent experiments that support the interdependent network theory in measurements of interdependent superconducting networks where a novel abrupt transition is observed due to microscopic interactions between the macroscopic systems although each isolated system shows a continuous transition.

S. Buldyrev, G. Paul, H.E. Stanley, S. Havlin, Nature, 464, 08932 (2010)
J. Gao, S. Buldyrev, H. E. Stanley, S. Havlin, Nature Physics, 8, 40 (2012)
A. Bashan et al, Nature Physics, 9, 667 (2013)
A Majdandzic et al, Nature Physics 10 (1), 34 (2014); Nature Comm. 7, 10850 (2016)
M. Danziger et al, Nature Physics  15(2), 178 (2019)
B. Gross et al, PRL  129, 268301 (2022)
I. Bonamassa, B. Gross, A  Frydman et al, Interdependent superconducting networks, Nature Physics (May 1, 2023)

- From Theoretical Physics to Experimental Neuroscience and Deep Learning Ido Kanter (BIU)
Ido Kanter (BIU)

Can Physics assist with key challenges in Neuroscience and Artificial Intelligence? Are current theoretical techniques of statistical mechanics capable of dealing with brain dynamics? Let us swim against the stream when scientific evidence tells you something is wrong.

Century-old assumptions regarding neurons and brain learning are disproved. According to the long-lasting computational scheme, each neuron sums the incoming electrical signals through its dendrites and when the membrane potential reaches a certain threshold the neuron typically generates a spike. We present several types of experiments, indicating that each stochastic neuron functions as a collection of independent threshold units, where the neuron is anisotropically activated. In addition, experimental and theoretical results reveal a new underlying non-local mechanism for the fast brain learning process, dendritic learning, as opposed to learning which is based solely on slow synaptic plasticity, where just one single neuron can realize deep learning algorithms. Though the brain is a very slow machine, its capabilities exceed typical state-of-the-art ultrafast artificial intelligence algorithms; hence, a revolution in deep learning must emerge.  


- Laser Plasma Accelerators Victor Malka (Weizmann)
Victor Malka (Weizmann)

Laser Plasma Accelerators (LPA) rely on our ability to control finely the electrons motion with intense laser pulses. Such manipulation allows to produce giant electric fields with values in the TV/m exceeding by more than 3 orders of magnitude those used in current accelerator technology. Controlling the collective electrons motion permit to shape the longitudinal and radial components of these fields that can be optimized for delivering high quality electrons beam or energetic photons.

To illustrate the beauty of laser plasma accelerators I will explain the fundamental concepts we recently discovered, with also some recent results from the Weizmann Institute of Science, and I’ll show the maturity of our approach in delivering particle and radiation beams for societal applications including for radiotherapy with the ebeam4therapy EIC project.

- Spintronics in the age of ChatGPT Lior Klein
Lior Klein

The launch of ChatGPT has been a remarkable milestone in the development of artificial intelligence (AI) and has captured widespread attention. However, current computing hardware presents limitations for AI development, particularly for edge computing. Neuromorphic computing systems, utilizing in-memory analogue computation, are a promising solution that is attracting significant interest. Among them, a spintronic realization based on a magnetic tunnel junction (MTJ) crossbar is gaining momentum. Unfortunately, the current MTJs are constrained to only two resistance states, posing significant limitations. In this talk, I will present our research efforts towards developing a new type of MTJ that supports multiple resistance states, facilitating the realization of a significantly more efficient spintronic crossbar to be used in future AI applications.

David Andelman (TAU)

The Poisson-Boltzmann theory stems from the pioneering works of Debye and Onsager and is considered even today as the benchmark of ionic solutions and electrified interfaces. It has been instrumental during the last century in predicting charge distributions and interactions between charged surfaces, membranes, electrodes, macromolecules, and colloids. The electrostatic model of charged fluids, on which the Poisson-Boltzmann description rests and its statistical mechanical consequences have been scrutinized in great detail. Much less, however, is understood about its probable shortcomings when dealing with various aspects of real physical, chemical, and biological systems. After reviewing the Poisson-Boltzmann theory, I will discuss several extensions and modifications to the seminal works of Debye and Onsager as applied to ions and macromolecules in confined geometries. These novel ideas include the effect of dipolar solvent molecules, finite size of ions, ionic specificity, surface tension, and conductivity of concentrated ionic solutions.

- Detecting anomalous asymmetries @ the (LHC) data Shikma Bressler (Weizmann and CERN)
Shikma Bressler (Weizmann and CERN)

Despite hundreds of searches for physics beyond the standard model (BSM), and hundreds of person years invested, no confirmed deviation from the standard model (SM) has been observed. Yet, the LHC data is far from being fully explored and BSM physics could be easily hidden in the already collected data. This calls for the development of new search approaches and methods. The Data Directed Paradigm (DDP) presented in this talk is one possible approach. While the DDP can be implemented exploiting different properties of the SM, here we discuss its implementation for symmetries of the SM. Its performance is demonstrated relative to traditional searches for lepton flavor violation and lepton non universality. 

- Measuring Entropy of Exotic Particles Yigal Meir (BGU)
Yigal Meir (BGU)

In recent years many candidate setups have been proposed to support exotic quasi-particles, such as Majorana fermions (MFs), which may be relevant for quantum computing, but whether these particles have been observed experimentally is currently a topic of a vivid debate. Entropy measurements can unambiguously separate these quasi-particles from other, simpler excitations. The entropy of a MFs is, for example, log2/2 (in units of the Boltzman constant), a fractional value that cannot be attributed to a localized excitation. However, standard entropy measurements applicable to bulk systems cannot be utilized in measuring the additional entropy of a mesoscopic device, which may be due to less than a single electron in the device. In this talk I will describe recent theoretical and experimental progress in performing such measurements, either using thermopower and/or using the Maxwell relations [1,2]. Particular examples will be single and double quantum dots in the Coulomb blockade regime. Lastly I will show how the formalism has been generalized to deduce the entropy from conductance measurements, and, applying it to a setup where two and three-channel Kondo physics have been observed, yields the fractional entropy of a single MF and a single Fibonacci anyon [3].  Lastly I will discuss the backaction of the measurement and discuss the possibility of measuring entanglement entropy [4].

[1]    Direct entropy measurement in a mesoscopic quantum system, N. Hartman, et al.,  Nature Physics 14, 1083 (2018).
[2]    How to measure the entropy of a mesoscopic system via thermoelectric transport, Y. Kleeorin et al., Nature Comm. 10 , 5801 (2019)
[3]    Fractional Entropy of Multichannel Kondo Systems from Conductance-Charge Relations, C. Han et al., Phys. Rev. Lett. 128, 146803 (2022).
[4]    Realistic protocol to measure entanglement at finite temperatures, C. Han, Y. Meir and E. Sela, Phys. Rev. Lett., 130, 136201 (2023).

- Propagation of radiation in diffusive media: modes, channels, localization Valentin Freilikher (Bar-Ilan University)
Valentin Freilikher (Bar-Ilan University)

Fluctuations of parameters that are ubiquitous in any real medium have pronounced, sometimes determining effect on the transport of wave radiation and quantum particles. Commonly encountered in nature is the diffusive regime, which has been extensively investigated for a long time, and nowadays is deemed to be well understood. Theoretically, it is usually studied in the framework of diffusion equations, which have proven to be quite efficient in explaining a wide variety of phenomena and experimental results in optics, acoustics, solid state physics, astronomy, biology, financial mathematics, etc. However, the issue with those equations is that they typically deal with ensemble-averaged quantities, which often have a little to do with the observations at a single random realization. Recently, it was discovered that, contrary to the common longstanding belief, the intensity of radiation propagating in a diffusive medium is not always homogeneously distributed. Under certain conditions, it is significantly structured: localized in the transverse direction in relatively narrow separated transmission channels, which are stretched along the sample and transmit the energy almost without leakage. The transmission coefficients and the incident and outgoing waveforms of these channels are given by the singular value decomposition of the transmission matrix, which connects the normal modes at the input to those at the output of a random sample. The unique physical properties of transmission channels open up new avenues for controlling the energy transmission and distribution inside a random medium, and for using it as a useful optical element. In my talk, a brief history and the current state of art in studying of the wave transport in diffusive media will be presented.

- Quantum computing with trapped-ion qubits Roee Ozeri (Weizmann)
Roee Ozeri (Weizmann)

Trapped-ions are one of the leading platforms for quantum computing technology with errors in the 10-6-10-3 level . In this colloquium Ill review basic methods and the status of trapped-ion quantum computing: different quantum gate schemes,  ion-trap fabrication and scale-up strategies. Ill also present recent results from our lab in which many-body coherent-control techniques are used to execute multi-qubit, robust gates.


- Memory, adaptation, and aging in crumpled sheets and networks of instabilities Yoav Lahini (TAU)
Yoav Lahini (TAU)

A thin sheet that has been crumpled many times exhibits many of the hallmark behaviors of driven and nonequilibrium disordered systems: intermittent global responses, emission of correlated crackling noise, slow relaxations and aging, and a range of mechanical memory effects. Here, through experiments in thin crumpled sheets and simulations of a minimal mechanical model, we reveal a microscopic, real-space, structural mechanism underlying and linking these behaviors.

Using experiments that combine global mechanical measurements, local probing, acoustic measurements, and 3D imaging of crumpled sheets, we build a mesoscopic description of their mechanics. The global measurements reveal a range of memory effects, including hysteresis, memory of largest strain, and return point memory, as well as clear signatures of underlying intermittent dynamics. Intermittent dynamics are also observed during slow, logarithmic aging of crumpled sheets under load. In this case, however, the intermittent events are grouped into highly correlated, scale-free avalanches. The complimentary local measurements reveal that intermittency, memory, and aging behaviors emerge from the collective dynamics of mesoscopic, bistable elements within the sheet: localized geometric instabilities that act as coupled, hysteretic, two-state degrees of freedom.

Based on this picture, we develop a numerical model of a disordered network of bistable elastic elements that corroborates all our findings: hysteresis, intermittencies, memory formation, return point memory, slow relaxations, aging, and avalanches. The model highlights the role of interactions and frustration between instabilities in driving these behaviors. The emerging picture is of a disordered system with a complex energy landscape, reminiscent of a mechanical spin-glass, that self-organizes to a state which lies on the verge of instability.


Shohat, D., Hexner, D. & Lahini, Y. Memory from coupled instabilities in unfolded crumpled sheets. Proc National Acad Sci 119, e2200028119 (2022).

Shohat, D. & Lahini, Y. Dissipation Indicates Memory Formation in Driven Disordered Systems. Phys Rev Lett 130, 048202 (2023).

Lahini, Y., Rubinstein, S. & Amir, A. Crackling noise during slow relaxations in crumpled sheets (in review)


Shohat. D., Friedman, Y. & Lahini, Y. Aging on the edge of stability in disordered mechanical systems (in review)


Prineha Narang (UCLA)

The re-invigorated field of electron hydrodynamics in quantum matter has recently garnered considerable scientific interest, both due to its technological promise of designing near dissipation-less nanoelectronics, as well as its fundamental importance as an experimental probe of strong electron-electron interactions. Investigating the capacity to which observations of electron hydrodynamic flows can inform the nature of electron-electron interactions is particularly important and timely with the advent of spatially-resolved transport measurements which, having demonstrated the hallmark spatial signature of electron hydrodynamic channel flow, must now turn their attention to studying more spatially-complex geometries, enabling the observation of intricate fluid phenomena such as vortices. Recently we have explored the effects of crystal symmetry on electron fluid behaviors starting from the most general viscosity tensors in two and three dimensions, constrained only by crystal symmetry and thermodynamics. In our work we demonstrate the anomalous landscape for electron hydrodynamics in systems beyond graphene, highlighting that previously-thought exotic fluid phenomena can exist in both two-dimensional and anisotropic three-dimensional materials with or without breaking time-reversal symmetry. In this context, the first part of my talk will discuss our recent predictions of hydrodynamics beyond graphene, especially the role of phonons in hydrodynamics in Weyl semimetals. We identify phonon-mediated electron-electron interactions, computed with techniques developed in the group that I will discuss in this talk, as critical in a microscopic understanding of hydrodynamics. The second part of my talk will introduce a new theoretical and computational transport framework from our group, the SpaRTaNS (Spatially Resolved Transport of Nonequilibrium Species) framework. I will discuss applications of this method in nonequilibrium electron and phonon transport in quantum matter. Time permitting, building on our recent work in magnetic Weyl semimetals, I will discuss possible approaches to understand and realize axion physics in condensed-matter systems.


References and links:

SpaRTaNS: Link to Github

1. Varnavides, G., Jermyn, A. S., Anikeeva, P., Felser, C. & Narang, P. Electron hydrodynamics in anisotropic materials. Nat. Commun. 11, 1–6 (2020).

2. Vool, U. et al. Imaging phonon-mediated hydrodynamic flow in WTe2. Nat. Phys. 17, 1216–1220 (2021).

3. Varnavides, G., Jermyn, A. S., Anikeeva, P. & Narang, P. Probing carrier interactions using electron hydrodynamics. arXiv [cond-mat.mtrl-sci] (2022).

4. Varnavides, G., Wang, Y., Moll, P. J. W., Anikeeva, P. & Narang, P. Finite-size effects of electron transport in PdCoO2. Phys. Rev. Mater. (2021) doi:10.1103/physrevmaterials.6.045002.

5. Wang, Y. & Narang, P. Anisotropic scattering in the goniopolar metal NaSn2As2. Phys. Rev. B Condens. Matter 102, (2020).

6. Osterhoudt, G. B. et al. Evidence for Dominant Phonon-Electron Scattering in Weyl Semimetal WP2. Physical Review X vol. 11 Preprint at (2021).

7. Coulter, J. et al. Uncovering electron-phonon scattering and phonon dynamics in type-I Weyl semimetals. Phys. Rev. B Condens. Matter 100, 220301 (2019).

8. Garcia, C. A. C., Nenno, D. M., Varnavides, G. & Narang, P. Anisotropic phonon-mediated electronic transport in chiral Weyl semimetals. Phys. Rev. Materials 5, L091202 (2021).

9. van Delft, M. R. et al. Sondheimer oscillations as a probe of non-ohmic flow in WP2 crystals. Nat. Commun. 12, 4799 (2021).

10. Coulter, J., Sundararaman, R. & Narang, P. Microscopic origins of hydrodynamic transport in the type-II Weyl semimetal WP2. Phys. Rev. B Condens. Matter 98, (2018).

11. Varnavides, G., Jermyn, A. S., Anikeeva, P. & Narang, P. Nonequilibrium phonon transport across nanoscale interfaces. Phys. Rev. B Condens. Matter 100, 115402 (2019).

12. Zhao, B., Guo, C., Garcia, C. A. C., Narang, P. & Fan, S. Axion-Field-Enabled Nonreciprocal Thermal Radiation in Weyl Semimetals. Nano Lett. 20, 1923–1927 (2020).

13. Nenno, D. M., Garcia, C. A. C., Gooth, J., Felser, C. & Narang, P. Axion physics in condensed-matter systems. Nature Reviews Physics 2, 682–696 (2020).

14. Mu, Q.-G. et al. Suppression of axionic charge density wave and onset of superconductivity in the chiral Weyl semimetal Ta2Se8I. Phys. Rev. Mater. 5, (2021).

- IPC talk: Bekenstein's Revolutionary Legacy Raphael Bousso (Berkeley)
Raphael Bousso (Berkeley)
Jacob Bekenstein was the first to treat black holes like material objects, allowing them to contribute to the entropy of the universe. By recognizing that Einstein’s seemingly classical theory of gravity is able to count its own quantum states and those of matter, he forged a profound relation between spacetime geometry and quantum information. 
Today, his insight is driving a golden age of progress. Gravity has been used to show that the universe behaves like a hologram; that information escapes from a black hole; and that what we perceive as energy density is really a change in the flow of quantum information.


- Pulsars and Magnetars: facts and possible fiction Nick Kylafis (Crete)
Nick Kylafis (Crete)

Anomalous X-ray Pulsars (AXPs) and Soft Gamma-ray Repeaters (SGRs) are relatively young, isolated neutron stars, that are thought to have super-strong ($10^{14} – 10^{15}$ G) dipole magnetic fields and even larger internal toroidal magnetic fields.  Thus, they were given the name Magnetars.  I will examine if this is a fact or possible fiction.  I will present an alternative picture and I will discuss what it will take to decide between the two pictures.


Prof. Maria Chekhova,

Spontaneous parametric down-conversion is the workhorse of quantum optics. It is used to generate entangled photon pairs and heralded single photons. When strongly pumped, spontaneous parametric down-conversion generates so many photon pairs that they overlap and form radiation with almost laser brightness. Nevertheless, this radiation manifests nonclassical effects: quadrature squeezing, photon-number correlations, and macroscopic entanglement. It has no coherent component and can be considered as amplified vacuum noise; it is therefore often called bright squeezed vacuum. In addition, strong photon-number fluctuations of bright squeezed vacuum make it extremely efficient for pumping multiphoton effects.

In my talk I will describe the quantum features of bright squeezed vacuum, and our recent experiments where we use it to pump multiphoton effects: optical harmonic generation and multiphoton photoelectron emission from nanotips. Further, I will speak about nonlinear interferometry, where two sources of parametric down-conversion are placed one after another to measure phase disturbances or absorption in between. Finally, I will show how a strongly pumped parametric amplifier can be used for the tomography of a quantum state, with immunity to loss and imperfect photodetection.


- Ships and seamanship based on underwater excavations in Israel Deborah Cvikel (University of Haifa)
Deborah Cvikel (University of Haifa)

For thousands of years, the Mediterranean Sea connected the people that lived along its shores – ancient coastal cities, ports and anchorages, shipwrecks and their cargoes, are all material evidence of human activity. The archaeological remains discovered on the seabed are cultural assets denoting the relationships that existed between man and the sea, and are an important pillar in the study of the history and archeology of the Mediterranean basin. A sunken ship represents a moment frozen in time, and underwater archaeology can offer a unique opportunity to explore and study this ‘time capsule’. The study of a shipwreck site can contribute new and valuable information on various aspects of seafaring, and enrich our understanding of the past. An overview of underwater excavations of ancient shipwrecks in Israel will be presented, followed by three case studies: the Ma‘agan Mikhael II replica ship; the holding power of Bronze Age stone weight anchors; and the 19th century Akko 1 shipwreck.

- Persistent Spontaneous Symmetry Breaking at High Temperatures Eliezer Rabinovici (CERN)
Eliezer Rabinovici (CERN)

I will describe the results of a series of works in which we have found systems for which Spontaneous Symmetry Breaking(SSB) persists to very high temperatures. 
The systems involve Conformal Field Theories of scalars in fractional dimensions 3<d<4-\epsilon and for Gauge Theories in d=4.
The systems are studied in the limit of various large numbers of species. In the process we have found non supersymmetric
conformal manifolds as well as cases of non supersymmetric effective potentials with flat directions. The SSB results in the formation of a dilaton. We also discuss  some phase diagrams in the presence of relevant and marginally relevant operators made out of scalar fields in d=4.

- A Statistical Physics Approach to Bacteria under Strong Perturbations Nathalie Balaban (HUJI)
Nathalie Balaban (HUJI)

Statistical physics successfully accounts for phenomena involving a large number of components using a probabilistic approach with predictions for collective properties of the system. While biological cells contain a very large number of interacting components, (proteins, RNA molecules, metabolites, etc.), the cellular network is understood as a particular, highly specific, choice of interactions shaped by evolution, and therefore difficultly amenable to a statistical physics description. Here we show that when a cell encounters an acute but non-lethal stress, its perturbed state can be modelled as random network dynamics. Strong perturbations may therefore reveal the dynamics of the underlying network that are amenable to a statistical physics description. We show that our experimental measurements of the recovery dynamics of bacteria from a strong perturbation can be described in the framework of physical aging in disordered systems (Kaplan Y. et al, Nature 2021). Further experiments on gene expression confirm predictions of the model. The predictive description of cells under and after strong perturbations should lead to new ways to fight bacterial infections, as well as the relapse of cancer after treatment.

- Ultracold lithium few-body puzzles Lev Khaykovich (Bar-Ilan)
Lev Khaykovich (Bar-Ilan)

A ubiquitous property of ultracold gases is the tunability of two-body interactions. When these interactions are resonantly enhanced, the quantum mechanical scattering problem supports weakly bound three-body states with universal properties. The latter means independence of details of the short-range interaction potentials and a discrete scaling invariance. Various aspects of this universality have been successfully demonstrated theoretically and experimentally in several atomic species in a recent decade. Lithium, however, remains a notable exception stubbornly refusing to concur with the emergent framework. In this talk I shall overview the subject and describe an increasingly involved theory-experiment collaborative effort to reveal the physics responsible for this puzzling behavior. 

- Network-free approach for microbial networks Amir Bashan (Bar-Ilan University)
Amir Bashan (Bar-Ilan University)

Human-associated and environmental microbial communities play important roles in their ecosystems. These communities consist of trillions of micro-organisms of typically hundreds of different taxa, which interact with each other and with their environment, represented as tangled ecological networks. Understanding these networks is key to understanding their dynamics and developing control strategies. However, reliable reconstruction of such large networks is a very challenging task, especially where the available data is limited. In my talk, I will review recent studies where we developed and applied a top-down approach to studying microbial networks, such as the `universality’ of their dynamics [1], their `effective connectivity' and its relation to May's stability criterion [2], detection of keystones [3], and if time permits, I will briefly present new results on the analysis of single-time-point microbial samples.

1) Universality of human microbial dynamics, Bashan A. et al, Nature (2016).
2) Complexity–stability trade-off in empirical microbial ecosystems, Yonatan Y. et al, Nature Ecology & Evolution (2022).

3) Top-down identification of keystone species in the microbiome, Amit G. and Bashan A., bioRxiv

- Entanglement in 'Dirty' Quantum Magnets Itamar Kimchi (Georgia Tech)
Itamar Kimchi (Georgia Tech)
Studying quantum entanglement over the past decade has allowed us to make remarkable theoretical progress in understanding correlated many-body quantum systems. However in real materials electrons experience spatially random heterogeneities ("dirt") whose theoretical treatment, including strong correlations, has been a challenge. I will describe how synthesizing ideas from quantum information theory, statistical mechanics, and quantum field theory gives us new insights into the role of randomness in 2D correlated quantum spin ("qubit") systems, enabling us to understand a broad variety of experimental observations. I will also describe how these results lead us to conjectures of general UV-to-IR constraints ("Lieb-Schultz-Mattis") on all possible behaviors of quantum magnets, even with randomness; and further to our current research on disordered topological insulators with anomalous boundary localization, as well as other novel quantum phases across connecting magnetic insulators to metals. 
- Electrons in flat wonderland Debanjan Chowdhury (Cornell)
Debanjan Chowdhury (Cornell)

Novel phases of matter can emerge when electrons are confined to two-dimensions, and have a significantly reduced kinetic energy relative to their interaction energy. The remarkable discovery of numerous interacting phases of matter, including superconductivity, in highly tunable devices made out of graphene and other semiconducting materials in recent years are challenging many of our established theoretical paradigms. I will begin by highlighting the conceptual difficulties with describing superconductivity in the limit where the electronic kinetic energy is quenched, where the standard theory due to Bardeen-Cooper-Schrieffer no longer applies. I will address the “universal” ingredients that set the superconducting transition temperature, in this non-perturbative limit. I will also revisit an old experimental puzzle in condensed matter physics, namely how a metal--an electrical conductor--transitions continuously into an electrical insulator with increasing strength of electronic interactions, inspired by experiments at Cornell.

- New Directions for Light Dark Matter Yonit Hochberg (HUJI)
Yonit Hochberg (HUJI)

Dark matter is one of the biggest mysteries of modern day physics, yet its identity remains unknown. In this talk, I will focus on light dark matter. From the theory side, I will discuss new theoretical developments that suggest light dark matter. From the experimental side, I will present new proposals for the direct detection of light dark matter which hold much promise. These include the use of superconducting nanowires, two-dimensional targets such as graphene, and heavy fermion materials. Considering dark matter interactions with these targets, I will demonstrate the potential of the light dark matter direct detection program in upcoming years.

- Photonic fault-tolerant quantum computing, and how single atoms can drastically simplify it Barak Dayan (Weizmann)
Barak Dayan (Weizmann)

The photonic effort is one of the leading candidates for universal quantum computing. In particular, it is the only technology that has been originally designed to reach the massive scaling required for fault-tolerant universal quantum computation (> million physical qubits). In my talk I will describe the photonic approach, which combines topological error correction and measurement-based quantum computation. I will then describe how cavity-QED with single atoms can drastically simplify this effort, solve its main bottleneck, and improve its scaling to even larger numbers of physical qubits.

1) Fusion-based quantum computation: arXiv:2101.09310 [quant-ph]
2) Photon-Atom Qubit SWAP gate: Nature Physics 14 996 (2018)

- Characterizing the inheritance dynamics and the inertia of cellular properties in bacteria Hanna Salman (Pittsburgh University)
Hanna Salman (Pittsburgh University)

Living cells with identical genome exhibit variability in their physical and functional properties. This variability is generated by cell proliferation (i.e. cells become different from each other over time as they grow and produce offspring), which suggests that properties are unreliably inherited between consecutive generations. But what is the extent of unreliability of inheritance? Do cellular properties exhibit Markovian dynamics, or do they have long-term memory? Obtaining quantitative answers to these questions will enable us to uncover the sources that contribute to generating variability among genetically identical cells. It will also allow us to develop accurate description of how the properties of cells will change over time. In this talk I will present our study in which, we measure the inheritance dynamics in bacteria, and reveal how it contributes to regulating various cellular properties (size, growth rate, etc.) in future generations. This is achieved using a new novel microfluidic device that enables us to track how sister cells become different from each other over time. Our measurements provide the inheritance dynamics of different cellular properties, and the ‘inertia’ of cells to maintain these properties along time, i.e. cellular memory. We find that certain cellular properties exhibit long memory that extends up to ∼10 generations.

- Science with gravitational lensing: From cosmic telescopes to cosmic microscopes Adi Zitrin (Ben Gurion)
Adi Zitrin (Ben Gurion)

Gravitational lensing (GL) has played various key roles in physics and astronomy, from the first proof for general relativity, to highlighting the need for a dark matter component. GL is currently used for a range of science from mapping the invisible dark matter to detecting exo-solar planets. In this talk I will review recent advancements in GL-related science. Among these, are the lensing of distant stars, supernovae, gamma-ray bursts, fast radio bursts, and gravitational waves. I will highlight key results mainly with respect to insights on dark matter and on the first galaxies in the universe, as well as our contribution to these fields and the relation to the recently launched James Webb Space Telescope.

- Quantum Computers – Secrets and Promises Eliahu Cohen (Bar-Ilan University)
Eliahu Cohen (Bar-Ilan University)

Much interest is attracted nowadays towards quantum computers. Both academy and industry wish to develop the right hardware and software which could benefit the most from the principles of quantum mechanics. However, many questions are still open, namely, why is it that only special problems have, at the moment, efficient quantum algorithms to solve them? Why is the advantage that quantum algorithms provide, compared to classical ones, vary so much from problem to problem? What are the most fundamental ingredients that make a quantum algorithm successful and what is the optimal balance between them? How can we systematically devise new quantum algorithms?

These are hard problems, which I cannot fully solve at the moment, but 1) I think that they are interesting and important. 2) I feel that we should discuss them more often these days. 3) I would like to present in my talk some suitable background and then our first attempts at solving them.

After a general overview I will present some unique quantum features underlying quantum algorithms, e.g. quantum nonlocality [1,2], uncertainty and non-commutativity [3], quantum discord [4], and mostly, irrealism [5]. I will then address our more recent approach which attempts to analyze quantum algorithms as communications channels via the mutual information between the output of the computer and the parameter it wished to find or estimate.

[1] Carmi A., Cohen E.,"Relativistic independence bounds nonlocality", Sci. Adv. 5, eaav8370 (2019).
[2] Cohen E., Carmi A., "In praise of quantum uncertainty", Entropy 22, 302 (2020).
[3] Carmi A., Herasymenko Y., Cohen E., Snizhko K., "Bounds on nonlocal correlations in the presence of signaling and their application to topological zero modes", New J. Phys. 21, 073032 (2019).
[4] Peled B.Y., Te'eni A., Carmi A., Cohen E., "Correlation Minor Norm as a Detector and Quantifier of Entanglement", Sci. Rep. 11, 2849 (2021).
[5] Paiva I. L., Dieguez P. R., Angelo R. M., Cohen E., "Coherence and realism in the Aharonov-Bohm effect", under review in Phys. Rev. A, arXiv:2209.00480.

Eitan Lerner (HUJI)

There are various approaches to gain insights at the macromolecular level from fluorescence-based assays, some of which depend on the structure of the fluorophores and photophysical effects they exhibit stemming from their structure. The effect of excited-state cis-trans isomerization occurring in fluorophores that act as molecular rotors in excited-state can be used if the de-excitation of one isomer exhibits high fluorescence quantum yield while the other exhibits a lower fluorescence quantum yield. In photoisomerization-related fluorescence enhancement, or PIFE, the potential steric obstruction of isomerization and its effect on fluorescence is used for reporting local structural changes. The combination of the PIFE effect with bright fluorescent dyes allows performing such measurements at the single-molecule level(1–4) or in fluorescence imaging.

In my talk, I will provide the fundamentals of PIFE, its uses in general, and in particular for studying differing questions:
(i) Do intrinsically disordered proteins (IDPs), exhibit only rapid structural transitions between unstable states, or do they also exhibit slow structural dynamics rendering them not well-folded proteins, but also not fully polymer-like ones(4–6). In this part I will summarize single-molecule PIFE measurementsin vitro using the organic dye, sulfo-Cy3, to site-specifically tag residues of the Parkinson's disease-related protein α-synuclein. The results of this part support the larger project of showing that the free monomer α-synuclein exhibits different well-defined conformational states, some of which are stable enough to act as promoters of function.
(ii) How can the phase of heterochromatin protein (HP) condensates be discerned experimentally from cellular fluorescence imaging? Here, I will summarize how can fluorescence lifetime imaging of standard fluorescent proteins can be useful, via PIFE, to sense local densities within dense phases, such as ones occurring in HP biocondensates. Using this approach, I will show that a liquid phase cannot explain HP biocondensates before
differentiation in mouse embryonic stem cells, however after initial differentiation, this changes towards a liquid phase.



  1. E. Ploetz, E. Lerner, F. Husada, M. Roelfs, S. Chung, J. Hohlbein, S. Weiss, T. Cordes, Förster Resonance Energy Transfer and Protein-Induced Fluorescence Enhancement as Synergetic Multi-Scale Molecular Rulers. Scientific Reports. 6, 33257–33257 (2016).
  2. E. Lerner, E. Ploetz, J. Hohlbein, T. Cordes, S. Weiss, A Quantitative Theoretical Framework For Protein-Induced Fluorescence Enhancement-Förster-Type Resonance Energy Transfer (PIFE-FRET). The Journal of Physical Chemistry B. 120, 6401–6410 (2016).
  3. E. Lerner, T. Cordes, A. Ingargiola, Y. Alhadid, S. Chung, X. Michalet, S. Weiss, Toward dynamic structural biology: Two decades of single-molecule Förster resonance energy transfer. Science. 359, eaan1133–eaan1133 (2018).
  4. S. Zaer, E. Lerner, Utilizing Time-Resolved Protein-Induced Fluorescence Enhancement to Identify Stable Local Conformations One α-Synuclein Monomer at a Time. JoVE, e62655–e62655 (2021).
  5. J. Chen, S. Zaer, P. Drori, J. Zamel, K. Joron, N. Kalisman, E. Lerner, N. V. Dokholyan, The structural heterogeneity of α-synuclein is governed by several distinct subpopulations with interconversion times slower than milliseconds. Structure (2021), doi:10.1016/j.str.2021.05.002.
  6. P. D. Harris, E. Lerner, Identification and quantification of within-burst dynamics in singly labeled single- molecule fluorescence lifetime experiments. Biophysical Reports. 2, 100071 (2022).
- A statistical physics view of swarming bacteria Avraham Be'er, Ben Gurion University
Avraham Be'er, Ben Gurion University

ZOOM link:

A statistical physics view of swarming bacteria

Avraham Be'er, Ben Gurion University

Bacterial swarming constitutes one of the most studied examples of active matter, which is a broad class of non-equilibrium many-body system. Swarming is a complex group phenomenon during which thousands of self-propelled microscopic cells move collectively on surfaces in coherent whirls and flows, showing a variety of intricate effects. Why bacteria move that way, and how they cooperate to form this collective motion, are the two major questions that lie at the basis of my research. However, current active matter models fall short of explaining even the basic results obtained in experiments. For example, although swarming is not species-specific, some quantitative, and even qualitative results differ between mutants and species whose physics is very similar, suggesting a coupling between the physical and biological aspect of swarming. The talk intends to provide a field guide to the physics underlying bacterial swarming. I will introduce the phenomenon and describe some of the principle physical aspects of the dynamics. The conclusions stemming from the studies show the crucial contribution of physical mechanisms to this biological phenomenon. 


- Laser Defense Systems- Science Fiction Materializing Yehonathan Segev, Refael
Yehonathan Segev, Refael

Laser technology has advanced rapidly from the invention of the laser in the 1960’s to the Mega-Watt lasers of the late 1980’s.  Alongside the rapid technology development comes an expectation for laser defense systems which have long been a part of science fiction literature. Nevertheless, the latter have yet to be fielded, coining the popular joke that high power laser systems have been three years away from us, for three decades.  Over the last few years, the technology has matured and the operational need for this innovative and game-changing defense system has increased making their entrance to the battlefield imminent.

This Seminar describes how these systems work and focuses on the technological breakthroughs that finally allows their realization- fiber laser power scaling via beam combining, beam focusing and pointing and real-time atmospheric turbulence disturbance correction.


Yehonathan Segev has been the head of the R&D group that specializes in Laser Systems in Rafael Advanced Defense Systems LTD since 2020. He is with the group in Rafael since 2011, after receiving a PhD from the Weizmann Institute of Science.

- Collisionless shocks around the largest structures Uri Keshet, Ben Gurion University
Uri Keshet, Ben Gurion University

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Collisionless shocks around the largest structures

Uri Keshet, Ben Gurion University

Pristine collisionless shocks were recently detected around galaxy clusters - the largest objects ever to virialize, forming representative island universes on the nodes of the cosmic web. Although collisionless shocks were anticipated in the 1950s, we still have no self-consistent model for these natural particle accelerators, which boost charged particles to ultra-relativistic cosmic rays. Galaxy clusters, too, pose major open questions, with no self-consistent models for their global cooling stability, extended non-thermal emission, and unexpected spiral dynamics. I will outline our understanding, challenges, and new hints for both collisionless shock and galaxy cluster physics.

- Quantum Critical Metals Erez Berg, Department of Condensed Matter Physics, Weizmann Institute
Erez Berg, Department of Condensed Matter Physics, Weizmann Institute



Metallic quantum critical phenomena are believed to play a key role in many strongly correlated materials, including high temperature superconductors. Theoretically, the problem of quantum criticality in the presence of a Fermi surface has proven to be highly challenging. However, it has recently been realized that many models used to describe such systems are amenable to numerically exact solution by quantum Monte Carlo (QMC) techniques, without suffering from the fermion sign problem. I will review the status of the understanding of metallic quantum criticality, and the recent progress made by QMC simulations. The results obtained so far will be described, as well as their implications for superconductivity, non-Fermi liquid behavior, and transport in the vicinity of metallic quantum critical points. Some of the outstanding puzzles and future directions are highlighted.

- IPC lecture: Quantum gas in a box Prof. Zoran Hadzibabic ,Cambridge University
Prof. Zoran Hadzibabic ,Cambridge University

An IPC event

Zoom link:


Meeting ID: 948 8531 4520

Password: 192379

Quantum gas in a box

For nearly three decades, ultracold atomic gases have been used with great success to study fundamental many-body phenomena such as Bose-Einstein condensation and superfluidity. While traditionally they were produced in harmonic electromagnetic traps and thus had inhomogeneous densities, it is now also possible to create homogeneous samples in the uniform potential of an optical box trap. Box trapping simplifies the interpretation of experimental results, provides more direct connections with theory and, in some cases, allows qualitatively new, hitherto impossible experiments. I will give an overview of our recent experiments with box-trapped three- and two-dimensional Bose gases, focusing on a series of related experiments on non-equilibrium phenomena, including phase-transition dynamics, turbulence, and equilibration of closed quantum systems.

- Non-invasive nanoscale cross-sectional XUV imaging Gerhard G. Paulus, Helmholtz Institute Jena
Gerhard G. Paulus, Helmholtz Institute Jena

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Non-invasive nanoscale cross-sectional XUV imaging

I will discuss nanoscale imaging in the extreme ultraviolet (XUV) spectral region using high-harmonics produced by femtosecond laser radiation. As opposed to other XUV imaging approaches, our scheme can exploit the entire high-harmonic spectrum. In fact, it is the XUV incarnation of optical coherence tomography, albeit vastly differently implemented due to the challenges of XUV optics. Thus, it is referred to as XUV coherence tomography, XCT.

A particularly relevant application of XCT for the spectral range up to 100 eV are silicon-based samples. We have demonstrated depth resolutions of 20 nm and very high sensitivities. Buried oxide layers of a thickness of a few nanometers could be detected as well as buried monolayers of graphene. It is even possible to identify the material encapsulated in silicon and determine also properties like layer roughness without destroying the sample. A unique perspective is ultrafast imaging.

- Elucidating the Interactions between Mechanical and (Electro)-Chemical Properties of Battery Materials Özgür Çapraz, Oklahoma State University
Özgür Çapraz, Oklahoma State University


Elucidating the Interactions between Mechanical and (Electro)-Chemical Properties of Battery Materials

The reality of the sustainable energy policy requires higher energy density batteries for electrification of the transportation and more cost-effective batteries made of earth-abundant materials  for large-scale energy storage applications.  Diversification of battery chemistries is the key strategy to achieve the goal.  There are growing interest in beyond Li-ion battery technologies such as all-solid-state batteries, metal-air batteries and metal-ion batteries.  However, many of these battery chemistries are far away from the commercialization due to their unsatisfactory practical electrochemical performance. Lifetime and performance of the batteries depends on the (electro)-chemo-mechanical instabilities in the materials during battery operation. Elucidating the coupling between electrochemistry and mechanics of electrodes beyond Li-ion batteries is critical to design materials suitable for battery chemistries. In this talk, I will address provide examples for (electro)-chemo-mechanical instabilities in different battery chemistries.

Na-ion batteries have attracted attention in the search for cost-effective batteries with a minimum sacrifice on the performance for large-scale energy storage applications. However, the physical and chemical properties of Na is intrinsically different than Li-ions.  Lack of insight into the influence of alkali ions on the interfacial dynamics and mechanical degradations of electrodes limits the design of novel materials.  For high energy demanding applications such as electrical planes and vehicles, Li-O2 batteries are promising candidates because their theoretical energy density is almost ten times higher than the Li-ion batteries. However, they suffer from severe interfacial instabilities associated with sluggish kinetics of the redox reactions and the insulating nature of the reduced oxygen species on the cathode surface. Solid electrolytes offer a promising way to increase the energy density by allowing the utilization of Li metal as an anode material for electrical vehicle applications. Despite the growing interest in solid electrolyte-based Li metal batteries, the utilization of the technology is still hindered by solid-solid interactions and chemo-mechanical instabilities in all-solid-state batteries.

In this presentation, I will first describe in situ curvature and digital image correlation measurement techniques to probe the electro-chemo-mechanical responses of battery materials. Second, I will present the effects of larger charge carrier ions (Na-ion and K-ion) on the chemo-mechanical behavior of battery electrodes1,2.  Third, I will present the role of electrolyte chemistry on the reaction dynamics on the Li-O2 battery cathodes. In particular, I will discuss the linkage between mechanical deformations and electrochemical behavior in the Li-O2 battery cathodes3. Last, I will present the coupling between overpotentials and interfacial deformations in all-solid-state batteries4.



  1. B. Ozdogru & Ö. Ö. Çapraz et al., ACS Nano Letters, 21, 18, 7579–7586, 2021.
  2. B. Ozdogru & Ö. Ö. Çapraz et al., Electrochemical Science Advances, e2100106, 2021
  3. H. Dykes & Ö. Ö. Çapraz et al., J. Electrochem. Soc., 168, 110551, 2021.
  4. B. Ozdogru & Ö. Ö. Çapraz et al., ACS Applied Energy Materials, In Press, 2022.



Dr. Çapraz received his Ph.D. degree in Chemical and Biochemical Engineering with a Mechanical Engineering minor from Iowa State University in 2014. He was a post-doctoral researcher in the Beckman Institute at the University of Illinois at Urbana-Champaign until 2018. Currently, he is an assistant professor in the School of Chemical Engineering at Oklahoma State University since Fall 2018. His research focuses on electrochemical energy storage and conversion devices, in situ chemo-mechanical characterization techniques, and advanced materials. His research group is investigating chemical and mechanical failure modes in all-solid-state batteries, Li-air batteries, alkali metal-ion batteries, and pseudo capacitors. His research has been supported by various agencies such as National Science Foundation, the Department of Energy, Binational Science Foundation, NASA, Air Force, and Lee Wentz Foundation. He received prestigious NSF CAREER award and BSF Young Investigator Start-up award.

- Cancelled due to Illness Oren Cohen, Technion (cancelled)
Oren Cohen, Technion (cancelled)



- Correlations and topology in a hybrid compound Haim Beidenkopf, Weizmann Institute
Haim Beidenkopf, Weizmann Institute

Zoom link:

Haim Beidenkopf, Weizmann Institute


A small change in the crystal structure of a material can completely modify its electronic properties. This is the case in the transition metal dichalcogenide TaS2 where a slight rotation of the sulphur atoms from the trigonal prismatic 1H structure to the octahedral 1T varies it from a superconductor to a Mott insulator possibly hosting a spin liquid state. We have studied 4Hb-TaS2 that interleaves the 1T and 1H polytypes. This has allowed us to investigate using scanning tunneling spectroscopy the fate of a Mott insulator when coupled to a metal and the superconducting phase that results from sandwiching it with Mott insulating layers. In the former we find a quantum phase transition that can be induced by the STM tip, electric field and temperature which possibly signifies the onset of correlations among Anderson impurities (or of a Kondo lattice). In the latter we identify a topological nodal superconducting state which we attribute to interaction-promoted inter-orbital pairing.

- Suppression of Electrode Material Degradation by Using Surface Modifications Techniques Malachi Noked, Dept. of Chemistry , Bar Ilan U.
Malachi Noked, Dept. of Chemistry , Bar Ilan U.

Please note! We are back in room 301!


Suppression of Electrode Material Degradation by Using Surface Modifications Techniques


Powering most currently used portable devices, batteries ushered electronics into a new era of mobile energy, directly supporting and influencing our daily lives. However, the ever-increasing demand for energy storage devices with improved performances and is challenging the scientific community to develop new chemistries and morphologies of electrode materials (EM) to move beyond current technology toward electrochemical storage devices with higher energy density, superior power performance and significantly extended stability.

Understanding fundamental degradation mechanisms of EMs, and their mitigation strategies, are challenged by constraints of the liquid electrolyte environment and the complexity of electrode/electrolyte interphase formation, namely the solid electrolyte interphase (SEI) layer which forms, grows, and changes (on the electrode interface) with battery usage.  Accordingly, the research community is increasingly seeking new pathways to understand and control battery degradation, including new diagnostic and characterization methods as well as mitigation strategies (e.g., electrode surface treatments, electrolyte additives and artificial SEI layers).

In my talk I will demonstrate how surface modification of EMs, significantly suppress the degradation of the battery components (e.g. electrodes, and electrolyte) and facilitates long-term stability of the electrochemical device.

I will demonstrate how in our lab, we modify the surface of the EMs by either thin protection layer applied on its interface (using atomic/molecular layer deposition- M/ALD), or by surface reduction of high voltage cathode materials. I will farther show how we monitor In-Operando the degradation of the electrode\electrolyte interface using online electrochemical mass spectroscopy (OEMS), and will demonstrate the efficacy of our coating strategy in suppressing the degradation pathway of the Ems.

Priyamvada Natarajan, Yale University

Lecture in the IPC series

Priyamvada Natarajan, Yale University




Gravitational lensing by clusters of galaxies offers a powerful probe of theories of structure formation. The standard paradigm of a cold dark matter dominated Universe provides concrete predictions for  small-scale substructure properties including their abundance, radial distribution and lensing efficiency. I present recent exciting result that confront observationally inferred quantities that map dark matter on small-scales with predictions of cosmological simulations. The power and prospects for stress-testing the cold dark matter paradigm with lensing data will be discussed. With the upcoming data deluge new stringent tests of dark matter will become feasible and viable.


- Complex molecules in space: How do they form and how do they cool down? Yoni Toker, BIU
Yoni Toker, BIU


Complex molecules in space: How do they form and how do they cool down?

Although mostly empty and cold, the interstellar medium (ISM) is beaming with molecules, with over 200 different species already identified. The goals of laboratory astrophysics are to measure properties of molecules in conditions similar to those of the ISM in order to identify new species and understand the processes by which they are formed, destroyed, and the evolution of their internal energy. Recent years have seen the comissioning of the cryogenic storage ring (CSR), which is quickly establishing itself as the most advanced tool of laboratory astrophysics. In this talk the CSR will be introduced, and  our recent measurements on the cooling of symmetric molecules in the ISM will be discussed. In addition, our works on the intra-cluster bond formation will be presented, and their implication as possible mechanisms for formation of complex molecules in the ISM.

- Prof. Sharly Fleischer, TBD Sharly Fleischer, Tel Aviv University
Sharly Fleischer, Tel Aviv University
- Extreme Value Statistics: How Big is Big? David A. Kessler
David A. Kessler


  We present an introduction to extreme value statistics, the statistics of the largest of a series of random numbers.  We first discuss the case of independent variables drawn from a given distribution and show the origin of the 3 universality classes for long series, Gumbel (for exponentially decaying distributions), Frechet (for distributions that decay as a power-law) and Weibull (for bounded distributions).  We show how in practice Gumbel is a poor approximation and how to get more accurate formulas. We then turn to correlated variables, in particular those generated by a Langevin equation.  We show that the statistics of the continuously monitored process are different than those are any discrete sampling of the data,
and for long-time series and restoring forces that increase with distance, the correlations eventually become irrelevant and the extreme value statistics approach those of an uncorrelated series of the same length drawn from the equilibrium distribution.


- Quantum sensing with unlimited optical bandwidth Avi Pe'er, Bar Ilan University
Avi Pe'er, Bar Ilan University

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Quantum sensing with unlimited optical bandwidth

Avi Pe’er, Physics department and QUEST center for quantum technology, Bar Ilan University, Ramat Gan 52900 ISRAEL


Squeezed light is a major resource for quantum interferometric sensing below the shot-noise limit. However, standard squeezed interferometry methods suffer from two severe limitations: First, the detection bandwidth of squeezing-enhanced interferometry is inherently narrow because of the slow response (MHz to GHz) of photodetectors, which prevents efficient utilization of the optical bandwidth (tens of THz and more) for quantum applications; and second, current quantum sensing requires near ideal photo-detectors with unity efficiency, prohibiting applications, where ideal detection is not available. To overcome these limitations and harvest the orders-of-magnitude enhancement of the sensing throughput, a paradigm shift is required in terms of broadband quantum sources, detection schemes, and interferometric design.
I will present a set of new methods for sub-shot-noise sensing, based on nonlinear interferometry, which overcome these limitations. By placing the phase object in question between two parametric amplifiers in series, the first amplifier generates broadband squeezed light to interrogate the object and the second amplifier acts as an ideal broadband quantum detector to measure the object’s response. This technique is robust to detection inefficiency and provides an unprecedented optical bandwidth for quantum measurement, exceeding the possibilities of photodetectors by several orders of magnitude.
I will discuss in detail two specific examples of ultra broadband parametric-homodyne measurement [1] and of squeezing-enhanced Raman spectroscopy [2].

[1] Y. Shaked, Y. Michael, R. Vered, L. Bello, M. Rosenbluh and A. Pe’er, “Lifting the Bandwidth Limit of Optical Homodyne Measurement”, Nature Communications 9, 609 (2018).
[2] Y. Michael, L. Bello, M. Rosenbluh, and A. Pe'er, “Squeezing-enhanced Raman Spectroscopy”,  npj Quantum Information 5, 81 (2019).

[3] L. Bello, Y. Michael, M. Rosenbluh, E. Cohen and A. Pe’er, “Broadband complex two-mode quadratures for quantum optics”, Optics Express 29, 41282 (2021)

- IPS Colloquium - Roger Penrose (Bekenstein Memorial lecture) Roger Penrose, University of Oxford
Roger Penrose, University of Oxford

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Black-Hole Entropy: its Key Role in the 2nd Law of Thermodynamics

Observational cosmology reveals the presence, in the current universe, of supermassive black holes whose total entropy should easily dominate that of the entire universe, according to the fundamental Bekenstein-Hawking formula. But this was not always the case. At the time of the emission of the microwave background radiation, some 380,000 years following the Big Bang, the entropy contribution from gravitational effects was extremely tiny, that in the matter having been extremely close to the maximum that it could have been. For some reason, at the Big bang itself, gravitational degrees of freedom were enormously suppressed, thereby allowing the 2nd Law of Thermodynamics to operate, as gravitational degrees relentlessly became activated, leading to their domination in the black holes currently observed.
But what about the remote future? We must expect that this trend will continue, even to the final evaporation of the black holes in an ever exponentially expanding universe. A seeming paradox lies behind this picture, in the extreme difference between the singularity structure at the Big Bang, where gravitational degrees of freedom are strangely suppressed, and the very opposite in the singularities in black holes, whose singularities appear to have the maximum entropy possible. It is hard to see how any direct quantization of gravity can resolve this gross time-asymmetric puzzle. Indeed, it can be argued that any quantization of gravity cannot resolve this issue without, apparently, an accompanying “gravitization” of quantum theory, in which the fundamental “measurement problem” of quantum mechanics is also resolved. Such a theory is currently lacking, but various experiments are now under serious consideration, to test this very basic idea.
Nevertheless, a deeper understanding of the special nature of the Big Bang can be illuminated by examining it from the perspective of conformal geometry, according to which the Big-Bang singularity becomes non-singular, this being quite different from the situation arising from the singularities in black holes. In conformal geometry, big and small become equivalent, which can only hold for a singularity of the type we seem to find at the Big Bang. This situation is also relevant in relating the extremely hot and dense Big Bang to the extremely cold and rarefied remote future of a previous “cosmic aeon”, leading to the picture of conformal cyclic cosmology (CCC) according to which our Big Bang is viewed as the conformally continued remote future of a previous cosmic aeon. It turns out that there are now certain strong observational signals, providing some remarkable support for this highly non-intuitive but mathematically consistent CCC picture.

- Order from the disorder Roy Beck, Tel Aviv University
Roy Beck, Tel Aviv University

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Order from the disorder

Roy Beck
Tel Aviv University, Tel Aviv, Israel

The concept that a given amino-acid sequence will not form a 3D folded structure but still have biological functionality has developed only in the last ~15 years. The discovery rate and characterization of intrinsically disordered proteins have been increasing continually, becoming one of the fastest-growing areas of proteomics. It is now estimated that over 50% of eukaryotic proteins contain large intrinsically disordered regions involved in a wide range of cellular functions, including transcription, translation, signaling, and regulation of protein assembly. Structural flexibility and plasticity originating from the lack of an ordered structures suggest a significant functional advantage for these proteins, enabling them to interact with a broad range of binding partners.

In this colloquium, I will review the recent trends where statistical mechanics ideas transform our understanding of molecular biology. I will also present new peptide amphiphiles composed of an intrinsically disordered peptide conjugated to variants of hydrophobic domains. These molecules, termed intrinsically disordered peptide amphiphiles, exhibit a sharp pH-induced micellar phase transition from low-dispersity spheres to extremely elongated worm-like micelles. I will present various experimental characterizations of the transition and propose a theoretical model to describe the pH response, routed on the weak interactions between disordered proteins. I will also show the potential of the shape transition to serve as a mechanism for the design of a cargo hold-and-release application. Such amphiphilic systems demonstrate the power of tailoring the interactions between disordered peptides for various stimuli-responsive biomedical applications.


- How low can electronic resistance go? Ady Stern (Weizmann)
Ady Stern (Weizmann)

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How low can electronic resistance go?


Ady Stern (Weizmann)


Electronic resistance is a fundamental notion both in condensed matter physics and in everyday life, where it is a source of heating caused by electronic currents. Typically, resistance originates from electrons scattering off impurities. However, even a perfectly clean system harbors a resistance, inversely proportional to the number of its conduction channels. Recent theories have shown that scattering of the flowing electrons off one another reduces this resistance, raising the question of its lower bound. Here we show that for a fixed number of channels the resistance may be practically eliminated, and give a transparent physical picture of this elimination.  


- Quantum computing with superconducting resonators Dr. Serge Rosenblum, Weizmann
Dr. Serge Rosenblum, Weizmann

In this talk, we will explore one of the leading technologies for quantum computing: superconducting circuits. This is the technology used by Google, IBM and many others to build their quantum computers. We will review the underlying principles and the current status of this technology. We will then discuss our approach of encoding quantum information in superconducting resonators instead of in two-level systems. Resonator qubits hold promise to achieve coherence times far beyond the current state of the art, and offer new ways to error-correct the quantum information. We will present preliminary data of our progress towards this goal.


- Physical applications of infinite ergodic theory Eli Barkai, Bar Ilan
Eli Barkai, Bar Ilan


Physical applications of infinite ergodic theory

Eli Barkai

Fermi pointed out that the Hydrogen atom in a thermal setting is unstable, as the canonical partition function of this simple system diverges. We show how non-normalised Boltzmann Gibbs measure can still yield statistical averages and thermodynamic properties of physical observables, exploiting a model of Langevin dynamics of a single Brownian particle in an asymptotically flat potential [1]. The ergodic theory of such systems is known in  mathematics as infinite (non-normalisable) ergodic theory, a framework that is widely applicable from laser cooled gases to non-linear systems.

[1] E. Aghion, D. A. Kessler, and E. Barkai , Non-normalizable Boltzmann-Gibbs statistics to infinite-ergodic theory, Phys. Rev. Lett. 122, 010601 (2019)

- Quantum simulators: from the Fermi Hubbard model to quantum assisted NMR inference (IPC) Eugene Demler , ETH Zurich
Eugene Demler , ETH Zurich

Quantum simulators: from the Fermi Hubbard model to quantum assisted NMR inference

I will review recent progress of the optical lattice emulators of the Fermi Hubbard model. The new feature of these experiments is availability of snapshots of many-body states with single particle resolution. I will discuss new insight from these experiments on the properties of magnetic polarons in antiferromagnetic Mott insulators. I will also discuss the idea of using quantum simulators to perform inference of NMR spectra for biological molecules. Practical aspects of realizing this hybrid quantum-classical algorithm on currently available experimental platforms will be reviewed.

Meeting ID: 926 1403 5030

Password:  508567


- Unraveling the origin of the chirality-induced spin-selectivity effect Jonathan Dubi, Dept. of Chemistry, Ben Gurion University
Jonathan Dubi, Dept. of Chemistry, Ben Gurion University



When electrons are injected through a chiral molecule, the resulting current may become spin polarized. This effect, known as the chirality-induced spin-selectivity (CISS) effect, has been suggested to emerge due to the interplay between spin–orbit interactions and the chirality within the molecule. However, such explanations require unrealistically large values for the molecular spin–orbit interaction without any physical justification. Put simply, to date, the physical origin of  the CISS effect is unknown. 
Here, we present a theory for the CISS effect based on the interplay between spin–orbit interactions in the electrode, the chirality of the molecule (which induces a solenoid field), and spin-transfer torque at the molecule–electrode interface. Using a mean-field calculation with simple models for the molecular junction, we show that our phenomenological theory can qualitatively account for all key experimental observations, most importantly the magnitude of the CISS with realistic parameters. We also provide a set of predictions which can be readily tested experimentally, and show recent data to corroborate these predictions. 

S. Alwan & Y. Dubi, J. Am. Chem. Soc. 2021, 143, 35, 14235–14241.

- Symmetry breaking in the formation of chiral nanocrystals Gil Markovich, Tel Aviv University
Gil Markovich, Tel Aviv University


Symmetry breaking in the formation of chiral nanocrystals

Gil Markovich

School of Chemistry, Tel Aviv University

Chirality (lack of mirror symmetry) is a fundamental property of biomolecules (amino acids, proteins, nucleic acids, DNA, sugars), and an essential part of their complex structures. Remarkably, almost all such biomolecules are of a single handedness (homochirality), and the reason for this symmetry breaking is one of the key questions in understanding the origin of life.

We are interested in symmetry breaking in inorganic compounds. Many inorganic compounds crystallize in chiral space group, such as quartz, for example. Our group has been studying the breaking of left-right symmetry in the formation of nanocrystals of such compounds. We have shown, that using small chiral bio-molecules which interact with the crystals’ building blocks, it is possible to achieve such symmetry break. In particular, we have been working with the chiral TbPO4×H2O nanocrystals, and have shown that their handedness can be controlled by preparing the nanocrystals in the presence of certain natural chiral molecules, such as tartaric acid. We use circularly polarized luminescence measurements of Eu3+ dopant ions in the nanocrystals to follow the handedness and enantiomeric purity of the produced nanocrystals.[1] Using single particle circularly polarized luminescence microscopy we were able to determine the handedness of individual nanocrystals and confirmed that we obtain a single mirror image (enantiomer) of the terbium phosphate nanocrystals when prepared with tartaric acid molecules.[2] We also discovered that at low enough synthesis temperatures the nanocrystals (almost-) spontaneously, randomly break symmetry (in the presence of minute amounts of chiral material) and propose a model for the symmetry breaking effects in the nanocrystal formation. This kind of super-sensitive symmetry-breaking effects could serve as models for the riddle of homochirality of biomolecules at the origin of life.


  1. U. Hananel, A. Ben-Moshe, H. Diamant, G. Markovich, Proc. Natl. Acad. Sci. USA 116, 11159-11164 (2019)
  2. E. Vinegrad, U. Hananel, G. Markovich, O. Cheshnovsky, ACS Nano 13, 601–608 (2019).


- Hidden Cosmic-Ray Accelerators as an Origin of TeV-PeV Cosmic Neutrinos Dafne Guetta , Ariel Unviersity
Dafne Guetta , Ariel Unviersity

The latest IceCube data suggest that the all-flavor cosmic neutrino flux may be as large as 107 GeV/cm2/s/sr around 30 TeV. We show that, if astrophysical sources of the TeV-PeV neutrinos are transparent to gamma rays with respect to two-photon annihilation, a large fraction of the isotropic diffuse -ray background should originate from hadronic emission of such sources, independently of the production mechanism. Strong tensions with the diffuse gamma-ray data are unavoidable especially in hadronuclear (pp) scenarios. We further show that, if the IceCube neutrinos have a photohadronic (p) origin, the sources are expected to be opaque to 1–100 GeV gamma rays. With these general multimessenger arguments, we find that the latest data may indicate a population of CR accelerators hidden in GeV-TeV gamma rays. In this talk I discuss the possibility that neutrinos may come from jets of collapsing massive stars which fail to break out of the stellar envelope, and for this reason they are known as choked jets, or choked Gamma-Ray Bursts (GRBs). In this talk, I will show the neutrino flux and spectrum expected from these sources, focusing on Type II SNe. I will provide predictions of expected event rates for operating neutrino telescopes, such as ANTARES and IceCube, as well as for the future generation telescope KM3NeT. I will show that for GRB energies channelled into protons spanning between ~ 1051-1053 erg, choked GRBs may substantially contribute to the observed astrophysical neutrino flux, if their local rate is ~ 80-1 Gpc-3yr-1 respectively.

Since these sources are hidden in the gamma-rays, searches for x-ray and UV-ray counterparts from these sources are encouraged.

- A New Statistical Solution to the Chaotic Three-Body Problem Nicholas Chamberlain Stone, Hebrew University
Nicholas Chamberlain Stone, Hebrew University


The three-body problem is arguably the oldest open question in astrophysics and has resisted a general analytic solution for centuries. Various forms of perturbation theory provide solutions in portions of parameter space, but only where hierarchies of masses and/or separations exist. Numerical integrations show that bound, non-hierarchical triple systems of Newtonian point particles will almost always disintegrate into a single escaping star and a stable bound binary, but the chaotic nature of the three-body problem prevents the derivation of analytic formulae that deterministically map initial conditions to final outcomes. Chaos, however, also motivates the assumption of ergodicity. I will present a new statistical solution to the non-hierarchical three-body problem that is derived using the ergodic hypothesis and that provides closed-form distributions of outcomes (for example, binary orbital elements) when given the conserved integrals of motion. We compare our outcome distributions to large ensembles of numerical three-body integrations and find good agreement, so long as we restrict ourselves to "resonant" encounters (the roughly 50% of scatterings that undergo chaotic evolution). In analysing our scattering experiments, we identify "scrambles" (periods of time in which no pairwise binaries exist) as the key dynamical state that ergodicizes a non-hierarchical triple system. I will briefly discuss how the generally super-thermal distributions of survivor binary eccentricity that we predict have applications to many astrophysical scenarios. For example, non-hierarchical triple systems produced dynamically in dense star clusters are a primary formation channel for black-hole mergers, but the rates and properties of the resulting gravitational waves depend on the distribution of post-disintegration eccentricities.

- Quantum Dot Physics Using Atomic Defects in Ultrathin Tunnel Barriers Hadar Steinberg, Hebrew University of Jerusalem
Hadar Steinberg, Hebrew University of Jerusalem

[ZOOM link for hybrid participation -]

Quantum Dot Physics Using Atomic Defects in Ultrathin Tunnel Barriers

Hadar Steinberg

Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel

Quantum dots (QDs) are conducting regions which can localize few charge carriers, and where the energy spectrum is dominated by Coulomb repulsion. QDs can be as large as few hundreds of nanometers, or as small as a single molecules, their sizes depending on their physical realization – whether in two-dimensional materials, nanowires, molecular systems.

In my talk I will describe our work on a new type of an atomically-sized QD, realized in defects residing in ultrathin two-dimensional insulators. These defect-dots are found in layered materials such as hexagonal Boron Nitride (hBN), which we study by their assembly into stacked devices. By using graphene electrodes, we able to electronically couple to the QD, while allowing the QD energy to be externally tuned exploiting the penetration of electric field through graphene.

A consequence of the structure of our devices is that the defect QDs are placed at atomic distance to the conductors on both sides. I will show how the presence of such energy-tunable, atomically sized QDs at nanometer proximity to other conducting systems opens new opportunities for sensitive measurements, including use of QDs as highly sensitive spectrometers [1], or as single electron transistors, unique in their sensitivity to local electric fields at the nanometer scale [2]. I will discuss our future prospects of using defect QDs as quantum sensors.



1. Devidas, T.R., I. Keren, and H. Steinberg, Spectroscopy of NbSe2 Using Energy-Tunable Defect-Embedded Quantum Dots. Nano Letters, 2021. 21(16): p. 6931-6937.

2. Keren, I., et al., Quantum-dot assisted spectroscopy of degeneracy-lifted Landau levels in graphene. Nature Communications, 2020. 11(1): p. 3408.


News from the Gravitational-Wave Sky Alessandra Buonannao
Alessandra Buonannao

Zoom Link,  Meeting ID: 942 2865 5001, Password: 802363

The solution of the two-body problem in General Relativity is playing a crucial role in observing gravitational waves from binary systems composed of black holes and neutron stars, and inferring their astrophysical, cosmological and gravitational properties. After reviewing the synergistic approach that successfully combines analytical and numerical relativity to produce highly accurate waveform models, I will discuss the most compelling and puzzling findings from the most recent LIGO-Virgo observing run.

- Kepler space mission and the advance of our understanding of multiple exo-planet systems Tsevi Mazeh, Tel-Aviv University
Tsevi Mazeh, Tel-Aviv University

Zoom Link     Meeting ID: 445 992 8099

The Kepler space mission observed more than 150,000 stars continuously for more than four years, producing unprecedentedly precise light curves.

The Kepler data enabled detecting thousands of stars with transit-like light curves, many of which are circled by more than one planet. The talk will review how Kepler has advanced our understanding of multiple exo-planet systems. This includes the systems’ architecture, obtained by evidence for dynamical interaction between the planets, and the discovery of circumbinary planets.

- ?The Hall effect: what moves in a metal or a superconductor Assa Auerbach, Technion
Assa Auerbach, Technion

NOTICE: This is a hybrid colloquium, given from the Physics Auditorium, and broadcasted also via Zoom

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Title: The Hall effect:  what moves in a metal or a superconductor?

Speaker: Assa Auerbach, Department of Physics, Technion


The Hall resistivity has long been used to identify the mobile charge carriers in metals. 
However, transport theory has failed to explain several intriguing  ‘’Hall anomalies’’ in strongly correlated metals, superconductors, and thermal Hall effect in insulators.
Recent advances by our group include new formulas for the Hall coefficient, and a revised theory of flux flow in superconductors, which help us understand  the ‘’moving parts’’  in transport currents of these systems.

- Cosmology and Unification Raman Sundrum
Raman Sundrum

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I will explain how precision measurements and correlations within the Cosmic Microwave Background, Large Scale Galactic Structure and 21-cm Cosmology can probe the fundamental physics of extremely heavy particles, orders of magnitude beyond the reach of terrestrial particle experiments such as the CERN Large Hadron Collider. Intuitively, the production of heavy particles is due to the high “Hawking Temperature” during the universe’s “growth spurt” of Cosmic Inflation. This mechanism is generalized and applied to showing how we can experimentally test our most ambitious gauge-Higgs and higher-dimensional theories, such as (Orbifold) Grand Unification, Dark Sectors, and the Standard Model itself.

- Live form New York: Programmable Quantum Materials Dimitri Basov, Columbia University, USA
Dimitri Basov, Columbia University, USA

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Quantum materials offer particularly appealing opportunities for the implementation of on-demand quantum phasesThis class of materials host interacting many-body electronic systems featuring an intricate interplay of topology, reduced dimensionality, and strong correlations that leads to the emergence of “quantum matter’’ exhibiting macroscopically observable quantum effects over a vast range of length and energy scales. Central to the nano-optical exploration of quantum materials is the notion of polaritons: hybrid light-matter modes that are omnipresent in polarizable media. Infrared nano-optics allows one to directly image polaritonic waves yielding rich insights into the electronic phenomena of the host material supporting polaritons. We utilized this novel general approach to investigate the physics of on-demand hyperbolic exciton-polaritons in a prototypical atomically layered van der Waals semiconductor WSe2 and of infrared non-reciprocity in a current carrying graphene device[3].


[1] D. N. Basov, Ana Asenjo-Garcia, P. J. Schuck, X. Zhu & Angel Rubio, “Polariton panoramaNanophotonics 10, 549 (2021)

[2] A. J. Sternbach, S. Chae, S. Latini, A. A. Rikhter, Y. Shao, B. Li, D. Rhodes, B. Kim, P. J. Schuck, X. Xu, X.-Y. Zhu, R. D. Averitt, J. Hone, M. M. Fogler, A. Rubio, and D. N. Basov, “Programmable hyperbolic polaritons in van der Waals semiconductors” Science 371, 617 (2021).

[3] Y. Dong, L. Xiong, I.Y. Phinney, Z. Sun, R. Jing, A.S. McLeod, S. Zhang, S. Liu, F. L. Ruta, H. Gao, Z. Dong, R. Pan, J. H. Edgar, P. Jarillo-Herrero, L.S. Levitov, A.J. Millis, M. M. Fogler, D.A. Bandurin, D.N. Basov “Fizeau Drag in Graphene Plasmonics” to appear in Nature (2021); arXiv:2103.10831

- Electrostatic manipulation of High-Tc superconductivity: the hammer and the scalpel Javier E Villegas, CNRS
Javier E Villegas, CNRS

Electrostatic manipulation of High-Tc superconductivity: the hammer and the scalpel

Javier E. Villegas*

Unité Mixte de Physique, CNRS, Thales, Université Paris Saclay, Palaiseau, France

Field-effect devices based on oxide superconductors constitute an interesting playground to investigate a rich variety of physical phenomena. They also bear much potential for novel functionalities. To illustrate that, I will show transport experiments on junctions between oxide-superconductors and non-superconducting materials, in which the conductance is modulated by electric field effects via different mechanisms.

First I will briefly discuss the observation of quasiparticle tunnel electroresistance in superconducting junctions. The term “tunnel electroresistance” was formerly coined to describe a non-volatile resistive switching observed in ferroelectric tunnel junctions upon application of a voltage pulse. This effect, which has opened the door to a new class of memories, can be explained by subtle mechanisms related to the nonvolatile reversal of the ferroelectric polarization. Our experiments with superconducting electrodes demonstrate that the same electroresistance can be produced by a more prosaic mechanism: oxygen electro-migration and the resulting modification of the electrodes’ ground-state. Furthermore, we demonstrate that the electroresistance is orders-of-magnitude stronger for quasiparticles than for normal electrons1,2

Second, I will discuss the electrostatic manipulation of the proximity effect in cuprate superconductor/graphene junctions 3Here, the underlying mechanism is the controlled variation the graphene’s Fermi vector through electrical gating. This allows tuning electron interferences that modulate the Andreev reflection at the superconductor/graphene interface. Furthermore, a different type of interferences –this time controlled by the bias voltage– are observed which are due to geometrical resonances and the coherent propagation of electron/hole pairs in graphene.4

1.        Bégon-Lours et al. Phys. Rev. Mater. 2, 084405 (2018).

2.        Rouco et al. Nat. Commun. 11, 1 (2020).

3.        Perconte et al. Nat. Phys. 14, 25 (2018).

4.        Perconte et al. Phys. Rev. Lett. 125, 087002 (2020).


*In collaboration with: D. Perconte, V. Rouco, C. Ulysse, D. Bercioux, J. Trastoy, A. Sander, P. R. Kidambi, S. Hofmann, B. Dlubak, P. Seneor, F. S. Bergeret, R. El Hage, J. Grandal, J. Briatico, S. Collin, K. Bouzehouane, A.I. Buzdin, G. Singh, N. Bergeal, C. Feuillet-Palma, J. Lesueur, M. Varela, and J. Santamaría


Work supported by the ERC grant Nº 647100, French ANR grant ANR-15-CE24-0008-01 and COST “Nanoscale Coherent Hybrid Devices For Superconducting Quantum Technologies” - Action CA16218.

Talk will be via ZOOM: 

- Small Country, Big dreams Alina Colton, SpaceIL
Alina Colton, SpaceIL

:Zoom linkMeeting ID: 951 7512 2285

Password: 071333

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This talk will tell the story of a journey from earth to the moon, from fantasy to reality. The story of three young engineers who chose to challenge the exclusive club of superpowers in deep space travel, and found a whole nation joining them along the way. It’s a story of hope and heartbreak, of incredible accomplishments beside (nearly) impossible difficulties. It’s the story of children that fueled a spaceship with their hopes and dreams and sent a clear message: “Shoot for the moon and follow your dreams!”

- Study of Herpesviruses towards the development of novel anti-viral therapies Ronit Sarid, BIU
Ronit Sarid, BIU

Zoom Link:
Meeting ID: 445 992 8099

Kaposi's sarcoma, the most common AIDS-associated malignancy, is caused by a human herpesvirus, KSHV. Rare types of lymphoproliferative diseases are also arising from KSHV infection. Nevertheless, the details of KSHV infection and pathogenesis remain unclear. HSV-1, another human herpesvirus, is a common infectious agent that occurs worldwide and infects humans of all ages. The outcome of HSV-1 infection includes a wide variety of clinical manifestations, ranging from asymptomatic infection to oral cold sores and severe encephalitis.

Our research deals with basic questions related to these viruses that could potentially lead to the discovery of novel approaches for antiviral interventions. Three main topics will be presented in the seminar, including: Tracking virus infection by using recombinant viruses expressing fluorescent proteins and fluorescently-tagged viral proteins; Generation of virions lacking nucleic acid and characterization of their docking to the nuclear pores; and inhibition of virus infection by using composite nanoparticles that block the attachment of virions to host cells.

- Beating of artificial Cilia Jean-Francois Joanny, Collège de France and Institut Curie, Paris
Jean-Francois Joanny, Collège de France and Institut Curie, Paris

Zoom Meeting ID: 951 7512 2285

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Many biological systems use the beating of cilia either to propel themselves or to induce fluid flow around them. Recent experiments in the group of Pascal Martin at Institute Curie study the beating of self-assembled actin bundles anchored on a solid surface induced by myosin motors, which can be considered as artificial cilia. In addition to the beating pattern of each cilium, the experiment images a wave of myosin motors along the cilium.

Classical theories describe the beating cilium as a bending slender beam immersed in a viscous fluid dissipation being due to the external hydrodynamic drag of the viscous fluid. The beating is created by an active mechanism internal to the cilium and due to molecular motors.

I will present in this talk a very generic theory of cilia beating that includes the various types of external and internal dissipation and of active forces propelling the cilium and that explicitly considers the molecular motor distribution along the cilium. The theory is based on the entropy production on the cilium  and the various dissipative forces are obtained from Onsager force-flux relations. The active forces are related to myosin motor densities along the cilium obtained from binding and unbinding kinetics for the motors.

A simple version of this theory in two dimensions provides a quantitative description of the experiments on artificial cilia done in the group of Pascal Martin.

- Quantum simulations with quantum computers on the cloud Emanuele Dalla Torre, BIU
Emanuele Dalla Torre, BIU

Link to recording

Quantum computing holds the promise to solve specific computational problems much faster than any known classical algorithm. Current quantum computers are, however, too small and too noisy to perform useful calculations. In this talk I will follow a different route and show how to use these systems to study fundamental physical questions, and specifically those related to the dynamics of many-body quantum systems. I will focus on two specific applications of quantum computers on the cloud: the demonstration of the topological property of spin models [1] and the realization of a quantum system with long range interactions [2]. These works raise new basic questions concerning the effects of classical noise on quantum states of matter, and provide a useful benchmark for actual quantum computers.

1.         Daniel Azses, Rafael Haenel, Yehuda Naveh, Robert Raussendorf, Eran Sela, Emanuele G. Dalla Torre, Identification of symmetry-protected topological states on noisy quantum computers, Physical Review Letters 125, 120502 (2020)

2.         Mor M. Roses, Haggai Landa, Emanuele G. Dalla Torre, Simulating long-range hopping with periodically-driven superconducting qubits,



- Illuminating Antimatter: the ALPHA antihydrogen experiment at CERN Jeff Hangst, Aarhus Univesity and ALPHA collaboration
Jeff Hangst, Aarhus Univesity and ALPHA collaboration

Zoom Details:  Meeting ID: 951 7512 2285,    Password: 071333

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The ALPHA experiment at the Antiproton Decelerator is unique in its combined ability to produce, trap, and study atoms of antihydrogen - the simplest anti-atom. The Standard Model requires that hydrogen and antihydrogen have the same spectrum.  Transition frequencies in hydrogen can be measured with precisions of order 10-15.  The precision in antihydrogen at ALPHA is now of order 10-12, making atom/anti-atom comparisons among the most precise, direct tests of fundamental symmetries in Nature.  Also of fundamental interest is the gravitational behaviour of antimatter, the study of which is the goal of the new ALPHA-g experiment. I will discuss the decades of development necessary to achieve the latest groundbreaking results in ALPHA. Among the latter is the demonstration of laser cooling of antihydrogen, published last week in Nature.  I will then consider the future of spectroscopy and gravitational studies with antihydrogen in the era of CERN’s brand-new ELENA facility, which will deliver antiprotons to us in August of 2021.

- Lessons from the first neutron star merger Ehud Nakar, Tel Aviv University
Ehud Nakar, Tel Aviv University

Link to recording of the talk


The first gravitational wave detection of a neutron star merger, GW170817, opened the era of multi-messenger gravitational wave-electromagnetic (GW-EM) astrophysics. It is a special event in many levels and its follow-up campaign is probably the largest coordinated observational effort in astrophysics dedicated to a single event. It offers an unprecedented data set, and although it is only a single event, it provides remarkable insights about fundamental physics and astrophysics and revolutionizes our knowledge on neutron star mergers. In my talk, I will give an overview of the main lessons from this event.


Udi (Ehud) Nakar is a Professor of Astrophysics in Tel Aviv University since 2009. His main field of interest is high-energy astrophysics and in particular the physical processes that are active in sources of high energy radiation, cosmic-rays, neutrinos and gravitational waves. His studies combine high-performance computing numerical simulations and analytic work. He received, among other, the IPS prize for young scientists and the ERC starting grant. Ehud is a member of the Israel Young Academy.

- MINFLUX nanoscopy and related matters Prof. Stefan W. Hell, Max Planck Institute for Biophysical Chemistry, Göttingen & Max Planck Institute for Medical Research, Heidelberg
Prof. Stefan W. Hell, Max Planck Institute for Biophysical Chemistry, Göttingen & Max Planck Institute for Medical Research, Heidelberg

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Meeting ID: 951 7512 2285

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I will show how an in-depth description of the basic principles of diffraction-unlimited fluorescence microscopy (nanoscopy) [1-3] has spawned a new powerful superresolution concept, namely MINFLUX nanoscopy [4]. MINFLUX utilizes a local excitation intensity minimum (of a doughnut or a standing wave) that is targeted like a probe in order to localize the fluorescent molecule to be registered. In combination with single-molecule switching for sequential registration, MINFLUX [4-6] has obtained the ultimate (super)resolution: the size of a molecule. MINFLUX nanoscopy, providing 1–3 nanometer resolution in fixed and living cells, is presently being established for routine fluorescence imaging at the highest, molecular-size resolution levels. Relying on fewer detected photons than popular camera-based localization, MINFLUX nanoscopy is poised to open a new chapter in the imaging of protein complexes and distributions in fixed and living cells.


[1]  Hell, S.W., Wichmann, J. Breaking the diffraction resolution limit by stimulated emission: stimulated-emission-  depletion fluorescence microscopy. Opt. Lett. 19, 780-782 (1994).

[2]  Hell, S.W. Far-Field Optical Nanoscopy. Science 316, 1153-1158 (2007).

[3]  Hell, S.W. Microscopy and its focal switch. Nat. Methods 6, 24-32 (2009).

[4]   Balzarotti, F., Eilers, Y., Gwosch, K. C., Gynnå, A. H., Westphal, V., Stefani, F. D., Elf, J., Hell, S.W. Nanometer resolution   imaging and tracking of fluorescent molecules with minimal photon fluxes. Science 355, 606-612 (2017).

[5]  Eilers, Y., Ta, H., Gwosch, K. C., Balzarotti, F., Hell, S. W. MINFLUX monitors rapid molecular jumps with superior   spatiotemporal resolution. PNAS 115, 6117-6122 (2018).

[6]  Gwosch, K. C., Pape, J. K., Balzarotti, F., Hoess, P., Ellenberg, J., Ries, J., Hell, S. W. MINFLUX nanoscopy delivers   multicolor nanometer 3D-resolution in (living) cells.  (bioRxiv, doi:

- Interactions of light and sound waves in optical fibers and photonic integrated circuits Avi Zadok, Faculty of Engineerin, BIU
Avi Zadok, Faculty of Engineerin, BIU

Title: Interactions of light and sound waves in optical fibers and photonic integrated circuits

Prof. Avi Zadok, Faculty of Engineering and Institute for Nano-Technology and Advanced Materials, Bar-Ilan University. 


Link to recording

Abstract: The propagation of optical waves in media exerts forces that may stimulate the oscillations of acoustic waves. The acoustic wave, in turn, can scatter and modulate light. The interplay of the two wave phenomena has drawn the attention of researchers since the 1880's. Our group is studying light-and-sound interactions in standard optical fibers and in silicon-photonic integrated circuits. In this seminar, I will present some of our latest, yet unpublished results of the last year: Inter-polarization scattering in standard and polarization-maintaining fibers, optical stimulation of acoustic vortex beams, and integrated microwave-photonic filters with arbitrary transfer functions and few-MHz linewidths. 


Very short bio: Prof. Avi Zadok joined the Faculty of Engineering, Bar-Ilan University in 2009. His research interests include fiber optics, nonlinear optics, opto-mechanics, and photonic integrated circuits. Prof. Zadok was the Chair of the Israel Young Academy for the year 2019-2020. 

- Discovering New Physics with Cosmological Data Sets Cora Dvorkin, Harvard University, USA
Cora Dvorkin, Harvard University, USA

This is part of the Israel Physics Colloquium

Please observe start time 16:00 PM

Discovering New Physics with Cosmological Data Sets

Measurements of the Cosmic Microwave Background and the large-scale structure of the universe have made it possible to determine with great precision the universe's inventory, as well as properties of its initial conditions. However, there are profound questions that remain unanswered. Cosmological observations and galaxy dynamics seem to imply that 84% of all matter in the universe is composed of dark matter, which is not accounted for by the Standard Model of particles. The particle nature of dark matter is one of the most intriguing puzzles of our time. The wealth of knowledge which is and will soon be available from cosmological surveys will reveal new information about our universe. I will discuss how we can use new and complementary data sets to identify new physics at different scales.

- Quantum simulating fragile many-body effects Sebastian Huber, ETH Zurich
Sebastian Huber, ETH Zurich

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Meeting ID: 445 992 8099

Quantum simulations can be performed at various scales: Cold atoms or trapped ions are optimal platforms when it comes to the ultimate control over the individual constituents of the simulator. Twisted bi-layer materials, on the other hand, combine the powerful tuning knobs of the traditional simulators with the direct route to applications inherent to solid state systems. Fortunately, these intermediate scale simulators present us with theoretical challenges that arise from their complexity. In this talk I will present our attempts to understand the superconductivity in twisted bi-layer graphene and how topology might play a crucial role. 

- Attosecond pulses for capturing electron dynamics Prof. Anne L'Huillier - Lund University, Sweden
Prof. Anne L'Huillier - Lund University, Sweden

Since the beginning of the millennium, physicists know how to generate pulses of light of attosecond duration (1 as= 10-18 s), thus gaining access to this incredibly short time scale. This presentation will describe how attosecond pulses are generated when intense laser pulses interact with atomic gases, and what are their characteristics.

We will then show how these pulses can be used to investigate fast electron dynamics in atomic photoionization.


Meeting ID: 39 0317 8346

Password: 326163

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- Precision Tests of Fundamental Interactions and Their Symmetries using Exotic Ions in Penning Traps Prof. Klaus Blaum - MPIK, Heidelberg
Prof. Klaus Blaum - MPIK, Heidelberg

Zoom Link: Meeting ID: 39 0317 8346 Password: 326163

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An overview is given on recent mass and g-factor measurements with extreme precision on single or few cooled ions stored in Penning traps. On the one hand, mass measurements provide crucial information for atomic, nuclear and neutrino physics as well as for testing fundamental interactions and their symmetries. On the other hand, gfactor measurements of the bound electron in highly charged hydrogen-like ions allow for the determination of fundamental constants and for constraining Quantum Electrodynamics. For example, the most stringent test of CPT symmetry in the baryonic sector could be performed by mass comparison of the antiproton with H- and the knowledge of the electron atomic mass could be improved by a factor of 13.

- Nano-engineered platforms for neuronal regeneration Orit Shefi, Engineering, BIU
Orit Shefi, Engineering, BIU

קישור להקלטת ההרצאה


Nano-engineered platforms for neuronal regeneration

Orit Shefi, Ph.D.

Faculty of Engineering, Institute of Nanotechnologies and Advanced Materials, Gonda Brain Center

Bar Ilan University


The ability to manipulate and direct neuronal growth has great implications in basic science and tissue engineering. Physical mechanical forces, contact guidance cues and chemical cues play key roles in neuronal morphogenesis and network formation. In this talk I will present our recent studies of 2D and 3D nanostructured scaffolds as platforms for controlling neuronal growth. We grow neurons on substrates patterned with nanotopographic cues of different shapes and materials and study the effects on neuronal geometry and function. We compare neurons interfacing the nano-patterned substrates to neurons interfacing other neurons to reveal mechanisms translating interactions into neuronal growth behavior. In-vivo, neurons grow in a 3-dimensional (3D) extracellular matrix (ECM). Imitating the 3D environment resembling the in-vivo conditions is important for effective regeneration post trauma. We have chosen a collagen hydrogel system as the 3D ECM analog to best mimic the natural environment and develop methods to orient the collagen fibers and use them as leading cues for neurons. We also used magnetic manipulations, via MNPS, as mediators to apply forces locally on neurons and their environment and as drug carriers. Current efforts to implant these modified gels to bridge gaps in injured PNS models effectively will be presented.

- A Journey Through Active Matter Prof. Sriram Ramaswamy / Indian Institute of Science, Bangalore
Prof. Sriram Ramaswamy / Indian Institute of Science, Bangalore

Meeting ID: 39 0317 8346

Password: 326163

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Materials whose individual constituents consume free energy and move autonomously as a result are known as Active Matter, for which living systems are both inspiration and prime example. I will introduce the subject, summarise early results, and present recent and ongoing work with my students and colleagues, on organising principles, phase transitions, and surprises in the statistics and dynamics of active systems. 

- Emergent Gauge Fields and Topology in Quantum Matter Ashvin Vishwanath/Harvard University
Ashvin Vishwanath/Harvard University

Zoom Meeting ID:  939 0317 8346, Password: 326163

For decades, condensed matter systems have been studied within the framework of classical order parameters - i.e. the Landau-Wilson paradigm.  This has been recently extended with the rather complete understanding of topological states of noninteracting electrons. In this talk  I will focus instead on new physics that arises from the interplay of topology and strong interactions. A unifying theme will be the emergence of gauge fields rather than the classical order parameters of Landau theory. I will illustrate these general themes with two recent works. The first  proposes a route to realizing  a long sought after phase - the Z2 quantum spin  liquid - in a synthetic platform, an array of  highly excited (Rydberg) atoms [1]. A potential application to the engineering of naturally fault tolerant quantum bits will also be described. The second example describes a topological route to strong coupling superconductivity [2], which was inspired by  recent experimental observations in magic angle  bilayer graphene and related devices.

[1] arXiv:2011.12310. Prediction of Toric Code Topological Order from Rydberg Blockade.
Authors: R.
Verresen, M. Lukin and A. Vishwanath.
[2]arXiv:2004.00638. Charged
Skyrmions and Topological Origin of Superconductivity in Magic Angle Graphene. 

- Statistical physics of microbial growth: fluctuations, phase transitions and large deviations Ariel Amir, Harvard University
Ariel Amir, Harvard University


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Meeting ID: 445 992 8099

The observation that non-genetic variability is ubiquitous in microbial populations has led to a multitude of experimental and theoretical studies seeking to probe the causes and consequences of this variability. Whether it be in the context of antibiotic treatments or exponential growth in constant environments, variability has significant effects on population dynamics. I will first present a coarse-grained model for cell growth, inspired by the Langevin equation, which incorporates both biomass growth rate and generation time fluctuations. Building on it, we will connect single-cell variability to the population growth, showing that in contrast to the dogma growth-rate fluctuations may lower the population growth. Analogous results are derived in the case where the variability arises from the asymmetric partitioning of a cellular resource, where we find a phase transition between a regime where variability is beneficial to one where it is detrimental. We will also show that a population's growth rate can be inferred from a single lineage, with intriguing relations to large deviation theory.



- Novel Probes of Dark Matter Cora Dvorkin, Harvard University
Cora Dvorkin, Harvard University

Meeting ID: 939 0317 8346
Password: 326163
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Cosmological observations and galaxy dynamics seem to imply that 84% of all matter in the universe is composed of dark matter, which is not accounted for by the Standard Model of particles. The particle nature of dark matter is one of the most intriguing puzzles of our time. The wealth of knowledge which is and will soon be available from cosmological surveys will reveal new information about our universe. I will discuss how we can use new and complementary data sets to improve our understanding of the particle nature of dark matter. In particular, galaxy-scale strong gravitational lensing provides a unique way to detect and characterize dark matter on small scales. I will present advances in the analysis of gravitational lenses and identification of small-scale clumps using machine learning. I will introduce the convergence power spectrum as a promising statistical observable that can be extracted from strongly lens images and used to distinguish between different dark matter scenarios, showing how different properties of the dark matter get imprinted at different scales. I will also discuss the different contribution of substructure and line-of-sight structure to perturbations in strong lens images.



- Tricks and Traps: Low Energy Searches for High Energy Physics Guy Ron, HUJI
Guy Ron, HUJI

לינק להקלטת ההרצאה:…

Trapped radioactive atoms and ions have become a standard tool of the trade for precision studies of beyond SM physics. β decay studies, in particular, offer the possibility of detecting deviations from standard model predictions of the weak interaction which signal new physics. These ’precision frontier’ searches are complementary to the high energy searches performed by the LHC and other high energy/high luminosity facilities. I will present a general overview of magneto-optical, optical traps, and electrostatic traps, and their use for weak interaction studies. I will further present the new Hebrew University/Weizmann Institute/NRCN trapping program (TRAPLAB), recent experimental results, and future plans.

- Particle Physics meets Machine Learning Jesse Thaler, MIT
Jesse Thaler, MIT


Meeting ID: 939 0317 8346


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Modern machine learning has had an outsized impat on many scientifc fields, and particle physics is no exception. What is special about particle physics, though, is the vast amount of theoretical and experimental knowelde that we already have about many problems in the field. In this colloquium, I present two case studies involving quantum chromodynamics (QCD), at the Large Hadron Collider (LHC) highlighting the fascinating interplay between theoretical principles and machine learning strategies. First, by catalogining the space of all possible QCD measurements, we (re)discoverd technology relevant for self-dricing cars. Second, by quantifying the similarity between two LHC collisions, we unlocked a class of nanparametric machine learining techniques based on optimal transport. In addition to providing new quantitative insights into QCD, these techniques enable new ways to visualize data from the LHC.

- Multiply charged helium droplets: efficient breeders for clusters and nanoparticles Paul Scheier, Innsbruck University
Paul Scheier, Innsbruck University

Recording of the talk:…

Zoom link:

Meeting ID: 445 992 8099

Almost every existing method of cluster and nanoparticle formation leads to a wide distribution of sizes. Thus, the limiting factor in all cluster studies is creating a sufficiently high concentration of the desired species and separating them from the overall distribution [1]. Recently, we discovered that large helium droplets can become highly-charged [2]. The charge centers self-organize as two-dimensional Wigner crystals at the surface of the droplets and act as seeds for the growth of dopant clusters [3]. Cluster ions of a specific size and composition can be formed by this technique with unprecedented efficiency. Softlanding of metal nanoparticles formed in highly-charged helium droplets can be achieved by deposition onto a target surface. The figure below shows two transmission electron microscope images of amorphous carbon surfaces decorated with metal nanoparticles formed upon pickup into helium droplets. In the case of neutral droplets (left image, taken from [4]), a single nanoparticle is formed in every droplet and its size depends strongly on the size of the helium droplet. As a result, a wide size distribution of nanoparticles is observed and the deposition time was several hours. In contrast, pickup of gold vapor into highly-charged helium droplets (right image) results in a narrow size distribution of nanoparticles. Due to the fact that several hundred nanoparticles are formed simultaneously in one helium droplet, the deposition time was reduced to a few seconds. Several applications for cluster physics, ion spectroscopy and nanotechnology will be presented

- The magic of moiré quantum matter Pablo Jarillo-Herrero, MIT, USA
Pablo Jarillo-Herrero, MIT, USA

The understanding of strongly-correlated quantum matter has challenged physicists for decades. Such difficulties have stimulated new research paradigms, such as ultra-cold atom lattices for simulating quantum materials. In this talk I will present a new platform to investigate strongly correlated physics, namely moiré quantum matter. In particular, I will
show that when two graphene sheets are twisted by an angle close to the theoretically predicted ‘magic angle’, the resulting flat band structure near the Dirac point gives rise to a strongly-correlated electronic system. These flat bands systems exhibit a plethora of quantum phases, such as correlated insulators, superconductivity, magnetism, Chern insulators, and more. Furthermore, it is possible to extend the moiré quantum matter paradigm to systems beyond magic angle graphene, and I will present an outlook of some exciting directions in this emerging field.

Link to zoom:

Meeting ID: 939 0317 8346
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- The Age of Gravitational Wave Astronomy Ofek Brinholtz, Dept. of Physics, Bar Ilan University
Ofek Brinholtz, Dept. of Physics, Bar Ilan University

The lecture will take place via Zoom:  Meeting ID: 445 992 8099

Gravitational Waves were originally predicted in the 1910's by Einstein, and measured directly for the first time in 2015. In the 5 years since, they have become a household acquaintance and a cornerstone of astrophysical observations and discoveries. I will present their background, history, and how they have begun to shape current day astrophysics, as well as what is expected in the not-so-distant future.


Link to the recording of the lecture…

2D With a Twist Rafi Bistritzer - 2020 Wolfe Prize Laureate
Rafi Bistritzer - 2020 Wolfe Prize Laureate

2D systems have been in the focus of condensed matter physics for decades. Recently it was shown that a twist between a pair of 2D graphene sheets at a particular ‘magic angle’  transfers the bilayer system to the strongly interacting regime. In this talk I will explain the ‘magic angle’ theory and review recent experimental results that demonstrate why twisted 2D  systems provide an excellent playground for studying some of the most fundamental open questions in condensed matter physics.

The colloquium will take place via Zoom and can be accessed through the followin link:

Meeting ID: 445 992 8099

Nicolas Roch

Note: The colloquium will take place via ZOOM:

Meeting ID: 445 992 8099

Electromagnetic fields possess zero point fluctuations which lead to observable effects such as the Lamb shift and the Casimir effect. In the traditional quantum optics domain, these corrections remain perturbative due to the smallness of the fine structure constant. To provide a direct observation of non-perturbative effects driven by zero point fluctuations in an open quantum system we wire a highly non-linear Josephson junction to a high impedance transmission line, allowing large phase fluctuations across the junction [1]. Consequently, the resonance of the former acquires a relative frequency shift that is orders of magnitude larger than for natural atoms. Detailed modeling confirms that this renormalization is non-linear and quantum. Remarkably, the junction transfers its non-linearity to about thirty environmental modes, a striking back-action effect that transcends the standard Caldeira-Leggett paradigm. This work opens many exciting prospects for longstanding quests such as the tailoring of many-body Hamiltonians in the strongly non-linear regime, the observation of Bloch oscillations,or the development of high-impedance qubits.


[1] Léger, S., Puertas-Martínez, J., Bharadwaj, K. et al. Observation of quantum many-body effects due to zero point fluctuations in superconducting circuits. Nat Commun 10, 5259 (2019)

- Luminescence spectroscopy of isolated macromolecular ions in vacuo Steen Brøndsted Nielsen
Steen Brøndsted Nielsen

Note: The colloquium will take place thorough zoom via the link:

Meeting ID: 445 992 8099

There are many occurrences of fluorescence and bioluminescence in nature, e.g., the Green Fluorescent Protein (GFP) or the luciferase enzyme that is responsible for light emission from fireflies. The photoactive molecules within these two proteins are both negatively charged (anions) and are surprisingly non-fluorescent when isolated in vacuo. Which interactions with the protein microenvironment are needed to turn on the fluorescence? This question is not only interesting from a fundamental point of view but also in biotechnology. Indeed, much work is devoted to develop bright fluorescent proteins or dyes in the red region of the visible spectrum where tissue transmission is high. My group tackles the question from a bottom-up approach as we study isolated molecular ions in vacuo and their intrinsic photophysics. In addition to protein biochromophores, we are interested in ionic dyes that are used in Förster Resonance Energy Transfer (FRET) experiments. Our work is based on home-built instruments, one important one being LUNA (LUminescence iNstrument in Aarhus) that allows us to measure fluorescence from larger ions produced by electrospray ionization. We have used this setup to study rhodamine monomer cations as well as homodimers (two identical dyes) and heterodimers (two different dyes) where the two dye cations are separated by flexible methylene linkers or more rigid linear linkers. In the case of heterodimers we see clear evidence of FRET in gas-phase systems, i.e., energy transfer from the initially photoexcited donor dye to the acceptor dye. I will present the results and discuss how the presence of one dye significantly affects the other. One of our future goals is to turn on light emission from protein biochromophores, either by cooling to low temperatures or by the attachment of polar molecules. This may be accomplished with a new setup (LUNA2) where the luminescence cell (trap) is cooled to liquid nitrogen temperature.

Astrochemistry at the Cryogenic Storage Ring Holger Kreckel, MPIK, Germany
Holger Kreckel, MPIK, Germany

The Cryogenic Storage Ring (CSR) at the Max Planck Institute for Nuclear Physics in Heidelberg combines electrostatic ion optics with extreme vacuum and cryogenic temperatures [1]. The storage ring has a circumference of ~35 m, and the detectors are housed in experimental vacuum chambers that can be cooled down to 5K. It has been shown that within a few minutes of storage infrared-active molecular ions (e.g., CH+ [2] and OH-[3]) cool to their lowest rotational quantum states by spontaneous emission of radiation.

Equipped with an ion-neutral collision setup and a low-energy electron cooler, the CSR offers unique possibilities for astrochemical experiments under true interstellar conditions. We will present an overview of the capabilities of the CSR along with first experimental
results on collisions of neutral C atoms with various hydrogen molecular ions and on the electron recombination of HeH+ [4].

Please note: The colloquium will take place via zoom. Join the meeting via the link:

Meeting ID: Meeting ID: 445 992 8099

[1] R. von Hahn, et al., The Cryogenic Storage Ring CSR, Rev. Sci. Instrum. 87, 063115 (2016)

[2] A. O'Connor, et al., Photodissociation of an Internally Cold Beam of CH+ Ions in a Cryogenic Storage Ring, Phys. Rev. Lett 116, 113002 (2016)

[3] Ch. Meyer, et al., Radiative Rotational Lifetimes and State-Resolved Relative Detachment Cross Sections from Photodetachment Thermometry of Molecular Anions in a Cryogenic Storage Ring, Phys. Rev. Lett. 119, 02320 (2017)

[4] O. Novotny, Quantum-state-selective electron recombination studies suggest enhanced abundance of primordial HeH+, Science 365, 676 (2019)

Baruch Barzel, BIU

A major achievement in the study of complex networks is the observation that diverse systems, from sub-cellular biology to social networks, exhibit universal topological characteristics, such as the small world or the scale-free phenomena. Yet this universality does not naturally translate to the dynamics of these systems, hindering our progress towards a theoretical framework of network dynamics. The source of this theoretical gap is the fact that the behavior of a complex system cannot be uniquely predicted from its topology, but rather depends also on the dynamic mechanisms of interaction between the nodes, hence systems with similar structure may exhibit profoundly different dynamic behavior. To bridge this gap, we derive the patterns of network information flow, indeed, the essence of a network's behavior, by offering systematic translations of topological characteristics into the actual spatiotemporal propagation of perturbative signals.


Relevant papers:

  • Spatiotemporal propagation of signals in complex networks. Nature Physics 15, 403 (2019)
  • Patterns of information flow in complex networks. Nature Communications 8, 2181 (2017)
  • Universal resilience patterns in complex networks. Nature 530, 307 (2016)
  • Universality in network dynamics. Nature Physics 9, 673 (2013)
TBA Baruch Barzel, BIU
Baruch Barzel, BIU


TBA Bernd von Isendorf
Bernd von Isendorf


TBA Ora Entin, TAU
Ora Entin, TAU


Neuromorphic electronics: a beginning guide Isao H. Inoue, AIST, Japan
Isao H. Inoue, AIST, Japan

‘Neural network (NN)’ is one of the new buzz words, but ‘neuromorphic’ is barely known outside of geeky community. It means ‘to mimic biological architectures in the nervous system’. As is well-known, the nervous system is in extreme complexity; mimicking the whole architecture is impossible. Thus, the essential point is abstraction.The biological neuron, an electrically excitable cell that communicates with
each other, can be replaced by a nonlinear device (artificial neuron) with a threshold for logic functions. The biological synapse, a joint between two neurons, with neuroplasticity can be a memory device (artificial synapse). The artificial neurons and synapses lead to the formation of artificial NN (ANN), and the architecture of ANN is crucial. Ideally, the properties of the artificial neuron and synapse should
determine the architecture of ANN. If the artificial neuron can mimic ‘leaky-integrate and fire (LIF)’ property, and the artificial synapse can mimic ‘spike-time-dependent plasticity (STDP)’ property of the biological counterparts, a spiking neural network (SNN) is plausible. However, in the present research, algorithm plays the leading role to determine both the architecture and devices, though the biological nervous system does not have any algorithms at all. An interesting example is the deep-learning (DL) algorithm for multi-layer NN. Because of its remarkable success in highly efficient statistical processing (e.g., image recognition), development of DL algorithm and computer chip for multi-layer NN (i.e., DL accelerator) are believed to realise artificial intelligence. However, the brain does not work with any algorithms. Our brain consumes only 20W, while DL requires immense power (Alpha Go, which defeated world champion, needed 200 kW), because the algorithm requires huge logic calculations.
In this talk, I would like to give an introduction of the abstraction for preparing the neuromorphic devices and architectures. I would also like to discuss on how to escape from the kingdom of the DL algorithm for real brain-like low-power computation.

Short Biography
Dr Isao H. Inoue received BSc, MSc, and DSc degrees in Physics from the University of Tokyo in 1990, 1992 and 1999, respectively. He became a researcher with tenure at the Electrotechnical Laboratory (ETL) in 1992 and a senior researcher in 1999. From 1999 to
2001, Dr Inoue was a visiting scholar at Cavendish Laboratory, University of Cambridge. In 2001, the Japanese government reorganised ETL with several other national institutes to found the National Institute of Advanced Industrial Science and Technology (AIST). Since then, he has been a senior researcher of AIST trying to work on missing links between the fundamental physics and the emerging electronics: e.g., quantum critical phenomena and neuromorphic electronic devices.;

CRISPR Gene Correction: A New Horizon for Medical Care Ayal Hendel, BIU
Ayal Hendel, BIU

We are in the midst of a revolution in genome engineering and CRISPR-Cas9 technology was the spark. With unprecedented rapidity, this technology has provided a straightforward, robust, and specific method for genome engineering and gene correction. CRISPR-Cas9 is a technique that allows for highly rapid modification of DNA in genomes of organisms and/or of cells. Our research focuses on developing CRISPR genome engineering as curative therapy for genetic diseases. Our lab is particularly interested in applying genome engineering for gene therapy of genetic disorders of the blood and the immune system such as severe combined immunodeficiency (SCID) also commonly known as the “bubble boy” disease. SCIDs are a set of life threatening genetic diseases in which patients are born with mutations in single genes, and are unable to develop functional immune system. We believe that the ultimate cure for these diseases will be transplantation of gene-corrected stem cells that create normal and healthy immune system. To be able to apply this approach in the clinic, we must assure that the CRISPR genome engineering technology is efficient and safe. Hence, our research focuses on developing an optimized CRISPR genome engineering for robust, specific and non-toxic gene correction. In my talk I will present the concept of CRISPR genome engineering and its possible application in medicine. I will present some of our recent studies demonstrating enhanced CRISPR genome editing by using chemical alterations to the CRISPR system, enabling therapeutically relevant genome editing frequencies in stem cells of the blood and the immune system. Finally, I will also present our joint research with the Yakhini group on developing an approach to accurately measure CRISPR specificity. Overall, we believe that by advancing CRISPR technology our research will accelerate the bench to bedside path and will help in generating a clear trajectory towards future clinical trials.

Hydra Regeneration and the Physics of Morphogenesis Kinneret Keren, Technion
Kinneret Keren, Technion

Morphogenesis, the emergence of functional form in a developing organism, is one of the most remarkable examples of pattern formation in nature. Despite substantial progress, we still do not understand the organizational principles underlying the convergence of this process, across scales, to form viable organisms under variable conditions. We focus on the mechanical aspects of morphogenesis using Hydra, a small multicellular fresh-water animal, as a model system. Hydra has a simple body plan and is famous for its ability to regenerate an entire animal from small tissue pieces, providing a flexible platform to explore how mechanical forces and feedback contribute to the formation and stabilization of the body plan during morphogenesis. I will present our recent results showing that the nematic order of the supra-cellular actin fibers in regenerating Hydra defines a coarse-grained field, whose dynamics provide an effective description of the morphogenesis process. In particular, I will show that topological defects in the nematic order of the actin fibers act as organization centers of the morphogenesis process, with the main morphological features developing at defect sites. Finally, we aim to directly demonstrate that mechanical constraints can pattern the body plan during morphogenesis via mechanical feedback and I will describe our progress in this direction.

- Spreading Spin at No Charge: the Thermal Hall Effect in a Quantum Spin Liquid Efrat Shimshoni, BIU
Efrat Shimshoni, BIU

In solid materials where electrons are strongly interacting, their spin and charge may effectively split to separate degrees of freedom. An extreme manifestation of this phenomena is the complete freezing of the charge degree of freedom (which renders the material electric insulator) while charge-neutral spin excitations are potentially free to move. When such materials possess a crystalline structure that frustrates magnetic ordering, novel phases of matter can form at low temperatures due to the quantum nature of the spin degrees of freedom. Among the most exotic states of matter emerging in these systems are the so-called "spin liquid" phases. Under appropriate conditions, they possess an intriguing signature: a thermal Hall effect in the absence of electric current. I will describe a particular model for spin-1/2 particles on a frustrated lattice which supports such quantum phases, and the behavior of the resulting thermal Hall conductance in the presence of an external magnetic field. Most prominently, we find that tuning the magnetic field induces transitions among three distinct phases: a spin-insulating valence bond crystal, a metallic spin-liquid and a chiral spin-liquid; the latter is an analogue of a quantum Hall liquid in two-dimensional conductors. I will finally discuss the possible relation of these findings to experimental observations of the recent years.              

- Catching and reversing a quantum jump mid-flight Michel Devoret
Michel Devoret

Measurements in quantum physics, unlike their classical physics counterparts, can fundamentally yield discrete and random results. Historically, Niels Bohr was the first to hypothesize that quantum jumps occurred between two discrete energy levels of an atom. Experimentally, quantum jumps were directly observed many decades later in an atomic ion driven by a weak deterministic force under strong continuous energy measurement. The times at which the discontinuous jump transitions occur are reputed to be fundamentally unpredictable. Despite the non-deterministic character of quantum physics, is it possible to know if a quantum jump is about to occur? Our work1 provides a positive answer to this question: we experimentally show that the jump from the ground state to an excited state of a superconducting artificial three-level atom can be tracked as it follows a predictable “flight” by monitoring the population of an auxiliary energy level coupled to the ground state. The experimental results demonstrate that the evolution of the jump — once completed — is continuous, coherent, and deterministic. Based on these insights and aided by real-time monitoring and feedback, we then pinpoint and reverse one such quantum jump “mid-flight”, thus deterministically preventing its completion. Our findings, which agree with theoretical predictions essentially without adjustable parameters, lend support to the modern formulation of quantum trajectory theory; most importantly, they may provide new ground for the exploration of real-time intervention techniques in the control of quantum systems, such as the early detection of error syndromes.


  1. Z. Minev et al., Nature 570, 200–204 (2019)
Nathan Aviezer, BIU

Can one construct a thinking machine?  Is artificial intelligence on the road to producing a thinking machine?  As computer programs become more and more sophisticated, will computers eventually be able to think?  How far away are we from such a possibility?  What does one mean by “thinking”?  Will thinking computers be able to decide to injure people?  To enslave mankind or maybe even to destroy mankind?  What is the Chinese Room thought experiment proposed by John Searle?  What are the implications of this thought experiment?  What reactions has this thought experiment generated?

These are some of the questions that will be discussed in this talk.

The Large Synoptic Survey Telescope: Status Update and Prospects for Science Prof. Steven M. Kahn, LSST Director
Prof. Steven M. Kahn, LSST Director

The Large Synoptic Survey Telescope (LSST) is a large-aperture, wide-field ground-based telescope designed to provide a time-domain imaging survey of the entire southern hemisphere of sky in six optical colors (ugrizy).  Over ten years, LSST will obtain ~ 1,000 exposures of every part of the southern sky, enabling a wide-variety of distinct scientific investigations, ranging from studies of small moving bodies in the solar system, to constraints on the structure and evolution of the Universe as a whole.


The development of LSST is a collaboration between the US National Science Foundation, which is supporting the development of the telescope and data system, and the US Department of Energy, which is supporting the development of the 3.2 gigapixel camera, the largest digital camera ever fabricated for astronomy.  Approved in 2014, LSST is now well into construction, and is on track to beginning operations in 2022.  I will review the design and technical status of the Project, and provide an overview of some of the exciting science highlights that we expect to come from this facility.

- Bose fireworks and Hawking-Unruh radiation Cheng Chin (Chicago, USA)
Cheng Chin (Chicago, USA)

Quantum phenomenon in curved spacetimes is an intriguing research topic that aims to offer hints to the not-yet-known theory of quantum gravity. One famous prediction is the Hawking-Unruh effect, the manifestation of Minkowski vacuum in a reference frame with high acceleration. We simulate the transformation to an accelerating frame by parametrically driving a Bose-Einstein condensate of atoms. Above the critical threshold, the driven condensate suddenly emits many jets of matterwaves in all directions. The emission resembles fireworks and displays a Boltzmann distribution that resembles the Unruh radiation. The measured temperature and entropy are in excellent agreement with Unruh’s predictions. We further detect non-local quantum coherence and temporal reversibility of the matterwave emission, which are hallmarks that distinguish Unruh radiations from the classical blackbody radiation. Our results confirm the quantum nature of Unruh effect.

Haim Suchowski, TAU

Remarkable breakthroughs in science throughout history are inherently linked to advances in the study of light-matter interactions. The understanding of new physical concepts and the development of novel optical tools were the driving forces behind ground-breaking multi-disciplinary discoveries in a variety of research fields. For the past two decades we have witnessed major advances in nano-optics and ultrafast physics, allowing for the exploration of phenomena in higher spatial and temporal resolution than ever before. In my talk, I will present recent achievements of observation and control of ultrafast phenomena at the nanoscale. In particular, I will share our recent achievements in combining ultrabroadband sources with our scattering near field microscope allowing observation of the broad frequency response as well as the ultrafast transient dynamics of plasmonic systems. I will share experimental demonstration of coherent control of the nonlinear response of optical second harmonic generation in resonant nanostructures beyond the weak-field regime. Contrary to common perception, we show that maximizing the intensity of the pulse does not yield the strongest nonlinear exponential response. We show that this effect emerges from the temporally asymmetric photo-induced response in a resonant mediated non-instantaneous interaction, opening new and diverse applications for control of optical nonlinearities at the nanoscale.

On Matter Confined by Radiation Pressure Ari Laor, Technion
Ari Laor, Technion

Active Galactic Nuclei (AGN) can produce steady state luminosity which far exceeds the luminosity of a whole galaxy. Observations indicate dilute gas which is present close to the massive black hole which resides at the centre of AGN. The energy transmitted from the radiation to the gas is well studied, but the momentum transfer did not receive much attention. I will describe the universal structure induced by the incident radiation pressure, and how it can naturally explain a host of emission and absorption properties of the ambient gas. Possible relevance to other systems will be briefly mentioned.

A new attempt to solve the type Ia supernova problem Boaz Katz - WIS
Boaz Katz - WIS

Supernovae distribute most of the chemical elements that we are made of and are detected daily, yet we still do not know how they explode. Type Ia supernovae consist of most recorded supernovae and are likely the result of thermonuclear explosions of white dwarfs (common compact stars with mass similar to the sun and radius similar to earth), but what mechanism causes about 1% of white dwarfs to ignite remains unknown. I will describe our ongoing recent attempt to solve this puzzle that involves a new potential answer - direct collisions of white dwarfs in multiple stellar systems, new robust tools to compare explosion models to observations - in particular the use of global conservation of energy in emitted radiation,  and new key observations  - in particular late-time spectra of ~100 recent supernovae.

Chiral molecules and the electron spin Yossi Paltiel, HUJI
Yossi Paltiel, HUJI

The electron’s spin is essential to the structure of matter and control over the spin orientation opens avenues for manipulating the structure of molecules and materials.  The energy associated with interacting electron clouds changes with their relative spin orientation. Controlling the relative spin orientation of electrons located on two reactants (atoms, molecules, or surfaces) has proved challenging, however. Recent developments based on the Chiral Induced Spin Selectivity (CISS) effect show that the spin orientation is linked to molecular symmetry and can be controlled in ways not previously imagined. For example, the combination of chiral molecules and electron spin opens a new approach to (enantio)selective chemistry, by adsorbing chiral molecules on a superconducting surface the order parameter is changes.  In my talk I will review the theoretical concepts underlying the CISS effect and illustrates its importance by discussing some of its manifestations in Chemistry, Biology, Physics and Spin based device engineering.

Sharon Ruthstein, BIU

Copper's ability to accept and donate single electrons makes it an ideal redox cofactor, and thus one of the most essential metal ions to the survival of the cell. However, copper ions are also involved in the Fenton reaction and hence capable of driving the generation of hydroxyl radicals, which are deleterious to the cell. Hence, both prokaryotic systems as well as eukaryotic system have developed a considerable regulation mechanism to maintain negligible copper concentration, in the femtomolar concentration. E.coli cells, in common with the vast majority of bacterial cells, require copper for several important enzymes such as ubiquinole oxidases, Cu,Zn-superoxide dismutases, or cytochrome c oxidase. However, as was mentioned above, copper can be deleterious, making protective mechanisms necessary. Deciphering this regulation mechanism in bacteria, is tremendously important from two specific reasons: one over 70% of the putative cuproproteins identified in prokaryotes have homologs in eukaryotes, and thus resolving the copper cycle in prokaryotic systems will also shed light on the copper cycle in eukaryotic systems. Second, copper has been used throughout much of the human civilization as an antimicrobial agent. In this talk we will shed light on two important copper regulation systems in E.coli: the copper periplasmic efflux system, CusCFBA, and the Cu(I) metal sensor, gene expression regulation system, CueR. Using Electron Paramagnetic Resonance (EPR) spectroscopy, together with biochemical experiments, cell experiments, and computational methods we will present structural model for CusB and CueR in the apo and functional state. Then, based on the structural constraints and cell data we will explain their mechanism of action. Last, we will demonstrate how basic understanding of the function of these systems can assist us in designing new class of antibiotics.

On Matter Confined by Radiation Pressure Ari Laor, Technion
Ari Laor, Technion

Active Galactic Nuclei (AGN) can produce steady state luminosity which far exceeds the luminosity ofa whole galaxy. Observations indicate dilute gas which is present close to the massive black hole which resides at the centre of AGN. The energy transmitted from the radiation to the gas is well studied, but the momentum transfer did not receive much attention. I will describe the universal structure induced by the incident radiation pressure, and how it can naturally explain a host of emission and absorption properties of the ambient gas. Possible relevance to other systems will be briefly mentioned.

- Quantum Information in Electron Microscopes Ido Kaminer, Technion
Ido Kaminer, Technion

Since its inception, research of quantum optics has extended our understanding of light–matter interactions and enabled novel applications of such interactions. Until recently, all the work in this field has been focused on light interacting with bound-electron systems – such as atoms, molecules, quantum dots, and quantum circuits. In contrast, markedly different physical phenomena could be found in free-electron systems, the energy distribution of which is continuous and not discrete, implying tunable transitions and selection rules. Bound electrons typically have their transitions limited to the optical spectrum (visible, IR) or lower frequencies, while free electrons can have transitions in extreme UV and X-rays. Free electrons are also particularly useful as a probe of matter for spectroscopy and imaging of condensed matter effects.

We explore these ideas with a new experimental platform: a laser-driven electron microscope. With it, we observe the quantized interaction between relativistic free electrons and femtosecond laser pulses, which open intriguing prospects in quantum optics and quantum electrodynamics.

I will present my group's theoretical and experimental work in the field:We observed quantum phase-matching between an electron wave and a light wave, creating for the first time a free-electron comb. In such a coherent comb of quantized electron energies, a single electron is both accelerated and decelerated by simultaneously absorbing and emitting hundreds of photons. 

We developed the platform for studying cavity quantum electrodynamics at the nanoscale with free electrons and observed their coherent interaction with cavity photons. We directly measure the cavity photon lifetime and show more than an order of magnitude enhancement in the fundamental electron–photon interaction strength. These capabilities open new paths toward using free electrons as carriers of quantum information, as we explore with theory and experiments.

Magnetic resonance on the single spin level Yishay Manassen, Ben Gurion Univesrity
Yishay Manassen, Ben Gurion Univesrity

Single spin detection is one of the central challenges of nano science and technology. We have
developed an STM related technique for single spin magnetic resonance (ESR-STM). The importance
of such a technique is three-fold: chemical analysis on the nm or atomic scale; Single spin physics
(many of the new physical phenomena recently observed are spin related: High temperature
superconductivity; Dirac materials; topological insulators etc and quantum information and
computation using single spin qubits.)
We measure high frequency noise power densities in the STM tunneling current. When above a
single spin in an external magnetic field, it reveals peaks at the Larmor frequencies. This is done at
room temperature, and without spin polarized tunneling. In order to detect weak rf signals (of the order
of 1-3 pA) we use matching circuits, modulation techniques and sensitive detectors (spectrum
analyzers or rapid oscilloscopes).
ESR-STM measurements on different spin centers revealed g hyperfine and zero field splitting
tensors up to a single spin levels. This reveals information on the local environment of the single spin
– which is not detectable microscopically. We use the hyperfine levels for doing single spin double
resonance measurements to detect the nuclear transitions. The experiments are performed on magnetic
atoms, defects or molecules. Studies to extend the technique for non magnetic species by ionization are
in progress.
Current results have demonstrated the capability to detect a single spin hyperfine spectrum of one
Tempo molecule. When there is another molecule nearby, the dipolar interaction between the
molecules, modifies the spectrum and enables to calculate the distance between the two molecules.
The distance is in agreement with the STM image. This ability may have broad applications for
example in questions of molecular docking or in molecular magnets

Eli Eisenberg. Tel Aviv University


RNA editing is a post-transcriptional process that allows for diversification of proteomes beyond the genomic blueprint, a phenomenon called "recoding". However, it is infrequently used among animals for this purpose. I will review the state-of-the-art understanding of recoding by editing, and discuss at length recent results showing that recoding is particularly common in behaviorally sophisticated coleoid cephalopods (e.g. squid and octopus). In particular, the trade-off between genome evolution and transcriptome plasticity will be suggested as a partial explanation for the rarity of recoding in most animal species.

Reconsidering nuclear and radiation hazards Yehoshua Socol, JCT
Yehoshua Socol, JCT

Nuclear and radiation hazards, historically linked to nuclear apocalypse, have been considerably overestimated. In the presentation, short consideration of nuclear detonations and their consequences (serious but far not apocalyptic) is followed by comparison to an interesting related phenomenon: nuclear-weapon-sized detonations of meteoroids in the atmosphere. Then, we proceed to considering radiation risks. The linear no-threshold (LNT) model, based on the assumption that every radiation dose increment constitutes increased cancer risk for humans, arose in late 1950-s concurrently with the nuclear arms race and massive governmental investment in science. Mistreatment of experimental (epidemiological) data systematically lent support to LNT. The presentation will describe our meta-analysis of several studies including Japanese atomic bomb survivors, Chernobyl and Fukushima residents, and children subjected to CT scans. The results of the meta-analysis show that (1) the Japanese data lack statistical power to support LNT, (2) recently-acknowledged overdiagnosis of thyroid cancer (reaching 90% and more of the reported incidence) is the main factor of increase in cancer incidence after Chernobyl and Fukushima, and (3) the data fit demonstrating increased risk of cancer after CT scans in childhood is "too good to be honest", so the data have been probably manipulated somehow. In addition, our recent analysis showed that even assuming LNT true, the present guidelines for population evacuation in case of radiological emergency are at least five-fold too stringent; the overall effect of such evacuations (including those after Chernobyl and Fukushima) is life shortening instead of the intended life extension.

Generating ‘Hot-Spots’ on Smooth Metallic Surfaces Adi Salomon, Chemistry department, BINA nano-center, Bar-Ilan University, Israel
Adi Salomon, Chemistry department, BINA nano-center, Bar-Ilan University, Israel

Controlling the optical field down to the nanometer scale is a key step in optoelectronic applications and light–matter interaction at the nanoscale. Bowtie structures, rods, and sharp tapers are commonly used to realize such optical properties, but their fabrication is challenging. In this context, the complementary structures, namely, holes and cavities, are less explored. Herein, a simple system of two metallic nanocavities milled in thin silver film is used to confine the electromagnetic field to an area of ≈60 nm2. The field is confined onto a flat surface area and is either enhanced or suppressed by the polarization state of incident light. The energy of this spatially confined mode is determined by the distance between the two cavities and thus any color (wavelength) at the optical regime can be achieved. As a consequence, a dynamically controlled color is generated on an optical pixel size smaller than 1 μm2. We further characterize those surfaces by a set of complementary spectroscopic technique among them; linear optical imaging, cathodoluminescence and second harmonic generation (SHG). A different mechanism for generating SHG is discussed, suggesting that the plasmons propagating onto the surface act as elementary particles and annihilate to form locally SHG spot.

(1) Galanty, M., Shavit, O., Aharon, H. Gachet, D. & Salomon, A.* Second Harmonic Generation Hot-Spot on a Centrosymmetric Smooth Silver Surface. light: Science and application

(2) Weissman, A.; Galanty, M.; Gachet, D.; Segal, E.; Shavit, O.; Salomon, A. Spatial Confinement of Light onto a Flat Metallic Surface Using Hybridization between Two Cavities. Adv. Opt. Mater. 2017,

(3) Segal, E.; Weissman, A.; Gachet, D.; Salomon, A. Hybridization between Nanocavities for a Polarimetric Color Sorter at the Sub-Micron Scale. Nanoscale 2016. (4) Grosse, N. B.; Heckmann, J.; Woggon, U. Physical Review Letters 2012, 108 (13), 136802.




Recent Discoveries and New Challenges in Time Domain Astronomy Iair Arcavi, Tel Aviv University
Iair Arcavi, Tel Aviv University

Novel wide-field transient surveys of the sky are finding new types of astronomical phenomena. I will discuss three classes of events we discovered recently: (1) peculiar new types of stellar explosions, which are challenging well-established models of supernova power sources; (2) the disruptions of stars by supermassive black holes, which are providing new insights into a decades-long problem; and (3) neutron stars mergers, which have brought the first observations of an astronomical event in both gravitational and electromagnetic waves, providing new insights (but also new puzzles) from the nuclear scale to the Universe as a whole. As more surveys come online in the coming years, we must develop the ability to define and identify the interesting events and obtain the crucial data in real time. I will briefly discuss how we're addressing this challenge.

Spectral manipulation of Raman amplifiers Ido Barth, Hebrew University
Ido Barth, Hebrew University

Backward Raman amplifiers provide a promising path to the next generation of short pulse high-intensity lasers that can go beyond the damage limit of conventional materials [1]. The main idea is to couple a short seed and a long counter-propagating pump through an electron plasma wave in such a way that the pump energy is transferred to the seed that is amplified and compressed via Raman backscattering. In the talk, I will give a short introduction on the physics of Raman amplifiers and review three recent developments in the field: (a) mitigating the relativistic phase-mismatch and the resulting saturation by detuning of the pump pulse [2], (b) multi-frequency amplification of pulses with a beat-wave waveform [3], and (c) a new configuration for Raman amplifiers in which, the laser seed is replaced by a plasma wave seed [4].

[1] V. M. Malkin, G. Shvets, and N. J. Fisch, Phys. Rev. Lett. 82, 4448 (1999).

[2] I. Barth, Z. Toroker, A. A. Balakin, and N. J. Fisch, Phys. Rev. E 93, 063210 (2016).

[3] I. Barth and N. J. Fisch, Phys. Rev. E 97, 033201 (2018).

[4] K. Qu, I. Barth, and N. J. Fisch, Phys. Rev. Lett. 118, 164801 (2017). 

Our place in cosmos Mario Livio, University of Nevada, Las Vegas
Mario Livio, University of Nevada, Las Vegas

I will present current thoughts on the place of humans (on Earth) in the grand cosmical scheme, in light of astronomical observations in the last few decades.

I will also discuss some philosophical implications of these findings.

Quantum and classical elasticity of graphene Igor Burmistrov, Landau Institute for Theoretical Physics
Igor Burmistrov, Landau Institute for Theoretical Physics

In this talk, I present an review of recent results [1,2,3] for the elastic properties of 2D crystalline membranes, including graphene. I discuss how an interplay between quantum and classical anharmonicity-controlled fluctuations leads to unusual elastic properties of the crystalline membrane. In particular, I discuss how anomalous Hooke’s law leads to the negative and almost constant thermal expansion coefficient in a wide temperature range and how the third law of the thermodynamics is restored at extremely low temperatures. Also, I discuss why the anomalous Hooke’s law is responsible for negative absolute and differential Poisson ratios of the crystalline membrane. I present the overall dependence of the Poisson ratio on the stress and the membrane size. I explain a possible reason of discrepancy in the results for the Poisson ratio between the self-consistent screening theory of membrane and numerical simulations.

[1] I.S. Burmistrov, I.V. Gornyi, V.Yu. Kachorovskii, M.I. Katsnelson, A.D. Mirlin, Phys. Rev. B 94, 195430 (2016).
[2] I.S. Burmistrov, I.V. Gornyi, V.Yu. Kachorovskii, M.I. Katsnelson, J.H. Los, A.D. Mirlin, Phys. Rev. B 97, 125402 (2018).

[3] I.S. Burmistrov, I.V. Gornyi, V.Yu. Kachorovskii, A.D. Mirlin, Annals of Physics 396, 119 (2018).

Imaging with scattered light Ori Katz, Hebrew University
Ori Katz, Hebrew University

Random scattering of light in complex samples such as biological tissue renders most objects opaque to optical imaging techniques, diffusing every focused beam into a complicated speckle pattern. However, although random, scattering is a deterministic process, and it can be undone and also exploited by controlling the incident optical wavefront, using computer controlled spatial light modulators (SLMs). These insights form the basis for the emerging field of optical wavefront-shaping [1]. Opening the path to new possibilities, such as imaging through visually opaque samples and around corners [2].

The major challenge in the field today is in determining the required wavefront correction without accessing the far side (target side) of the scattering sample.

I will present some of our recent efforts in addressing this challenge [3-8]. These include the use of optical nonlinearities [3], the photoacoustic effect [4-6], and acousto-optics [7] to focus and control light non-invasively inside scattering samples. I will also show how by exploiting inherent correlations of scattered light, it is possible to image through scattering layers and ‘around corners’ using nothing but a smartphone camera [8].

If time permits, I will present the use of these principles for endoscopic imaging through optical fibers [9-10].



[1] A.P. Mosk et al., "Controlling waves in space and time for imaging and focusing in complex media", Nature Photonics 6, 283 (2012).

[2] O. Katz et al., "Looking around corners and through thin turbid layers in real time with scattered incoherent light", Nature Photonics 6, 549 (2012).

[3] O.Katz et al., "Noninvasive nonlinear focusing and imaging through strongly scattering turbid layers", Optica, 1, 3, 170-174 (2014).

[4] T. Chaigne et al. "Controlling light in scattering media noninvasively using the photo-acoustic transmission-matrix.", Nature Photonics 8, 58 (2014).

[5] E.Hojman et al. "Photoacoustic imaging beyond the acoustic diffraction-limit with dynamic speckle illumination and sparse joint support recovery", Optics Express Vol. 25, Issue 5, pp. 4875-4886 (2017)

[6] T. Chaigne et al. "Super-resolution photoacoustic imaging via flow-induced absorption fluctuations", Optica Vol. 4, Issue 11, pp. 1397-1404 (2017)

[7] O. Katz et al. " Controlling light in complex media beyond the acoustic diffraction-limit using the acousto-optic transmission matrix", Nature Communications (2019)

[8] O. Katz et al., "Non-invasive single-shot imaging through scattering layers and around corners via speckle correlations", Nature Photonics, 8, 784–790 (2014)

[9] A.Porat et al., "Widefield lensless imaging through a fiber bundle via speckle-correlations", Optics Express (2016)

[10] SM Kolenderska, O Katz, M Fink, S Gigan Scanning-free imaging through a single fiber by random spatio-spectral encoding, Optics letters 40 (4), 534-537 (2015)

Superconductivity in the ultra-low density limit Jonathan Ruhman, Bar-Ilan University
Jonathan Ruhman, Bar-Ilan University

According to standard theory, systems with a low concentration of charge carriers, such as semiconductors and semimetals, are not expected to exhibit superconductivity. Their density of states is very small and their Fermi energy is of the same order as the Debye frequency of the crystal. Nonetheless, superconductivity is observed in many low-density systems. In this talk I will give an overview of the theoretical challenges in understanding this phenomena and discuss possible resolutions. I will then focus on a particular scenario, a crystal close to a ferroelectric quantum critical point, in which our theory predicts superconductivity at arbitrary low density.  

Mixed order phase transitions: from DNA denaturation to jamming processes David Mukamel, Weizmann Institute of Science
David Mukamel, Weizmann Institute of Science

Phase transitions of mixed nature, which on the one hand exhibit a diverging correlation length as in second order transitions and on the other hand display a discontinuous order parameter as in first order transitions have been observed in a diverse classes of physical systems. Examples include DNA denaturation, models of wetting, glass and jamming transitions, rewiring networks  and some one-dimensional models with long-range interactions. An exactly soluble Ising model which provides a link between some of these rather distinct classes of systems is introduced. Renormalization group analysis which provides a common framework for studying some of these systems, elucidating the relation between them will be discussed as well as the extreme value statistics of the locally ordered domains that characterize the various phases.

Hyperuniformity of driven suspensions Haim Diamant, Tel Aviv University
Haim Diamant, Tel Aviv University

An arrangement of particles is said to be "hyperuniform" if its density fluctuations over large distances are strongly suppressed relative to a random configuration. Crystals, for example, are hyperuniform. Recently, several disordered materials have been found to be hyperuniform. Examples are sheared suspensions and emulsions, and, possibly, random close packings of particles. We show that externally driven particles in a liquid suspension (as in sedimentation, for example) self-organize hyperuniformly in certain directions relative to the external force. This dynamic hyperuniformity arises from the long-range coupling, induced by the force and carried by the fluid, between the concentration of particles and their velocity field. We obtain the general requirements, which the coupling should satisfy in order for this phenomenon to occur. Under other conditions (e.g., for certain particle shapes), the coupling can lead to the opposite effect -- enhancement of density fluctuations and instability. We confirm these analytical results in a simple two-dimensional simulation.

Introduction to the quantum first detection problem Eli Barkai, Bar-Ilan University
Eli Barkai, Bar-Ilan University

We consider quantum dynamics on a graph, with repeated strong measurements performed locally at a fixed time interval τ. For example a particle starting on node x and measurements performed on another node x'. From the basic postulates of quantum mechanics the string of measurements yields a sequence no,no,no, ... and finally in the n-th attempt a yes, i.e. the particle is detected. Statistics of the first detection time nτ are investigated, and compared with the corresponding classical first passage problem. Dark states, Zeno physics, a quantum renewal equation, winding number for the first return problem (work of A. Grunbaum et al.), total detection probability, detection time operators and time wave functions are discussed.


[1] H. Friedman, D. Kessler, and E. Barkai, Quantum walks: the first detected passage time problem, Phys. Rev. E. 95, 032141 (2017). Editor's suggestion.

[2] F. Thiel, E. Barkai, and D. A. Kessler, First detected arrival of a quantum walker on an infinite linePhys. Rev. Lett. 120, 040502 (2018).

- Shake and sink: the physics of granular liquefaction Einat Aharonov, Institute of earth science, Hebrew University
Einat Aharonov, Institute of earth science, Hebrew University

Earthquakes often trigger soil liquefaction: Usually saturated soils behave like elastic solids, supporting buildings and structures. But shaking induced by an earthquake may cause soils to undergo a rheological transition whereby they start flowing like fluids. Earthquake-triggered liquefaction causes sinking and tilting of buildings, floatation of buried structures (e.g. gas pipes), and ground settlement. This is one of the largest hazards from earthquakes: For example, liquefaction triggered during the 1995 Kobe earthquake in Japan caused 5000 deaths and $ 200 billion in damage.

The classical mechanism for explaining earthquake-triggered liquefaction invokes a poorly drained, loosely packed, saturated soil (i.e. granular media) undergoing cyclic shear. The cyclic-shearing causes pore collapse. The pressure of fluid trapped in the pores (pore pressure) then rises till the fluid fully carries the weight of the grains, permitting complete loss of shear resistance. This view is what guides current engineering practices and building codes.

Field observations from around the world show however that this only part of the story: in contrast to this widely held view, liquefied soils may be fully drained, and initially densely packed. We develop a physics based theory for treating granular and fluid deformation, and use it simulate liquefaction in a coupled multi scale discrete element + fluid code. Our theory predicts the conditions for pore collapse and explores the conditions when subsurface fluid flow can cause liquefaction. It also explains why buildings sink during liquefaction, pipes float, how remote earthquakes can trigger liquefaction, and why liquefaction can occur some time after the earthquake has passed. These results may greatly impact hazard assessment and mitigation in seismically active areas.


The colloquium is cancelled.

Imaging Topological Materials Jenny Hoffman, Harvard Universtiy, USA
Jenny Hoffman, Harvard Universtiy, USA



Today’s electronic technology – the pixels on the screen and the process to print the words on the page – are all made possible by the controlled motion of an electron’s charge. In the last decade, the discovery of topological band insulators with robust spin-polarized surface states has launched a new subfield of physics promising a new paradigm in computing. When topology is combined with strong electron correlations, even more interesting states of matter can arise, suggesting additional applications in quantum computing. Here we present the first direct proof of a strongly correlated topological insulator. Using scanning tunneling microscopy to probe the real and momentum space structure of SmB6, we quantify the opening of a Kondo insulating gap. Within that gap, we discover linearly dispersing surface states with the heaviest observed Dirac states in any material – hundreds of times the mass of a free electron. We show how single atom defects can scatter these surface states, which paves the way towards manipulating single atoms and thus controlling surface states and their excitations at the nanoscale.



Real-space (left) and momentum-space (right) images of the topological surface states on SmB6.

The transverse flow of entropy in solids and electronic topology Kamran Behnia, CNRS & ESPCI France
Kamran Behnia, CNRS & ESPCI France

In the semiclassical picture of thermal and thermoelectric transport, heat-carrying quasi-particles such as electrons and phonons are scattered after traveling a finite distance. The two signatures of this picture are the Wiedemann-Franz law and Mott’s formula. The first part of this talk reviews our present picture of transverse thermoelectricity (Nernst) and transverse thermal (Righi-Leduc or thermal Hall) effects, with a focus on the extreme variety of the magnitude of the Nernst coefficient in metals explained by the semiclassical picture.

The second part of the talk is devoted to non-trivial electronic topology. The thermoelectric and thermal counterparts of the anomalous Hall effect arise because of the Berry curvature of electrons when the host solid lacks time-reversal symmetry. Our ongoing research aims to measure and to understand the transverse thermoelectric and thermal responses caused by the ‘anomalous velocity’ of electrons in magnetically-ordered solids.



Ofer Firstenberg

Warm atomic vapor is one of the simplest quantum systems, offering real-life applications in deployable centimeter-size devices. It strongly couples to optical fields and exhibits superb coherence properties at or above room temperature. Notably, atomic vapors are at the heart of miniature atomic clocks and inside the most sensitive magnetometers and gyroscopes. We explore schemes for realizing optical quantum memories in alkali vapors and noble-gases. We realize a fast ladder-type memory (FLAME) by mapping the optical field onto the superposition between electronic orbitals in rubidium. FLAME demonstrates GHz-bandwidth and extremely low noise, suitable for quantum network synchronization. We consider the implementation of FLAME via tapered fibers, and its integration with Rydberg-level excitations for quantum nonlinear optics. On the other side of the scale, we report on a record memory lifetime approaching one second at room temperature. The long lifetime is achieved by mapping the optical field onto ground-state spin orientation of cesium, which is insensitive to spin-exchange collisions. The scheme paves the way towards relying on spin exchange for coupling light coherently to noble-gas nuclear spins, with an alkali vapor serving as a mediator. If successful, this could leverage the hour-long coherence time of noble-gas spins for extreme quantum optics and sensing applications.


Understanding microsecond dynamics of protein machines with single-molecule fluorescence Gilad Haran, Weizmann Institute of Science
Gilad Haran, Weizmann Institute of Science

Protein machines carry out specific tasks in the cell by alternating chemical steps with conformational/structural transitions. Single-molecule fluorescence spectroscopy is a powerful tool for exposing large-scale function-related motions. We recently developed a sophisticated maximum likelihood algorithm for the analysis of single-molecule experiments, which can track conformational dynamics even on the microsecond time scale. In the lecture, I will show how this novel analysis helped us understanding the dynamics of two machines, an abundant enzyme and a protein that rescues other proteins from aggregation. 

Laboratory Astrophysics Studies along the Cosmic Cycle of Gas Daniel Wolf Savin, Columbia University
Daniel Wolf Savin, Columbia University

Tracing the evolution of baryonic matter from atoms in space to stars
such as our Sun hinges on an accurate understanding of the underlying
physics controlling the properties of the gas at every step along this
pathway. Here I will explain some of the key epochs in this cosmic cycle
of gas and highlight our laboratory studies into the underlying atomic,
molecular, plasma, and surface processes which control the observed
properties of the gas.

The role of a layer in deep learning Zohar Ringel, Hebrew University
Zohar Ringel, Hebrew University

Deep artificial neural networks (DNNs) have been driving many of the
recent advancements in machine learning. An important question on the
theory side of DNNs concerns the role played by each layer in the
network. Recently two bold conjectures were made: The first is that
DNNs learn to perform a series of Renormalization-Group (RG)
transformations on the data they are given. The second claims that
each subsequent layer in a DNN increases more and more a certain
conditional-entropy. In this talk, I’ll discuss some tests and
refinements of these two conjectures. In particular, I’ll present an
information-theory based formulation of real-space RG and compare it
with more conventional training algorithms for DNNs. Time permitting
I’ll also discuss the training of DNNs using the above
conditional-entropy based goal.

Relevant papers
[1] M. Koch-Janusz and Z.R. (2018)
[2] Z.R. and R. A. de Bem (2017)
[3] P. M. Lenggenhager, Z.R.,S. D. Huber, M. Koch-Janusz (2018)

Eran Sharon, Hebrew University

By combining the theory of incompatible elastic sheets with chemical analysis we introduce a new paradigm for the modeling and analysis of nano-scale self-assembled solid sheets. Analysis of molecular interactions provides inputs to the elastic model, which determines the supramolecular structure and its thermal fluctuations.

The approach is demonstrated in a combined experimental-theoretical study of nano-scale self-assembled ribbons, made of lipids and peptides with chiral head groups. We analytically derive quantitative predictions for ribbons configurations and shape fluctuations. These are confirmed experimentally, revealing unusual mechanics and statistics, indicating that the shape and mechanics of the suprasturactures are governed by geometrical incompatibility.


Light at the Horizon: Observation of Stimulated Hawking Radiation in Optics Ulf Leonhardt, Weizmann Institute
Ulf Leonhardt, Weizmann Institute

Hawking radiation has been one of the intellectually most influential predictions of theoretical physics, connecting general relativity with quantum mechanics and thermodynamics, but it has never been fully observed yet, even in laboratory analogues, despite admirable experimental progress made. Here we report on clear, non-ambiguous measurements of stimulated Hawking radiation in nonlinear fiber optics. Our experiment shows the surprising robustness of the Hawking effect in optics and may finally clear the path towards a full quantum demonstration.

Instabilities in dynamic fracture Eran Bouchbinder, Weizmann Institute of Science
Eran Bouchbinder, Weizmann Institute of Science

Cracks, the major vehicle for material failure, undergo various dynamic instabilities in brittle materials. Despite their fundamental importance and apparent similarities to other instabilities in condensed-matter and materials physics, these instabilities remain poorly understood. In particular, they are not explained by the classical theory of cracks, which is based on the linearized field theory of elasticity. We develop a 2D theory capable of predicting arbitrary paths of dynamic cracks, incorporating small-scale, near crack-tip elastic nonlinearity. We show that cracks undergo a high-speed oscillatory instability controlled an intrinsic nonlinear elastic length, in quantitative agreement with experiments. The instability is shown to exist, with the same salient properties, in materials exhibiting widely different near crack-tip elastic nonlinearity, highlighting its universal character. We further show that upon increasing the driving force for fracture, a tip-splitting instability emerges, which is experimentally demonstrated. The theory culminates in a comprehensive stability phase diagram of 2D brittle fracture.

Physics of non-Hermitian quantum Hamiltonians Nimrod Moiseyev, Technion
Nimrod Moiseyev, Technion

Physical Hamiltonians are not Hermitian (NH) when either the potentials are complex (as for example in optics when the index of refraction is complex) or when the potential is real but the system is in a metastable state (as for example in alpha decay or in an autoionization/photoionization of atoms and molecules). Physical phenomena that it is hard and often impossible to study by standard (Hermitian) quantum mechanics (QM) will be discussed. The focus will be on the discovery of physical phenomena that can be described in a simple way solely by the mean of NHQM.

Jacob Klein (Weizmann Institute of Science)

Whenever two surfaces are at nanometer separation, as when they are in or close to contact, even small potential differences (<0.5V) between them may result in extremely large electric fields (of order 108 V/m) across the intersurface gap. Such large fields can readily affect interfacial phenomena. My talk will describe recent results where interactions between a molecularly smooth mica surface and a gold surface at variable potentials are measured directly, shedding light on different phenomena from the charging dynamics of an individual nanopore to a remarkable control of friction through surface potential changes.

Super-oscillating beams of light and matter Ady Arie, Tel Aviv University
Ady Arie, Tel Aviv University

Super-oscillating functions are band-limited functions that oscillate
locally faster than their higher Fourier component. These functions were
studied in the past for wide ranging applications, including super-directive
antennas, weak measurements of quantum systems, imaging and microscopy. 
Here I will present new applications of super-oscillations for trapping and
manipulation of nano-particles, for generation of electron beams with
sub-diffraction central spot, for realization of nonlinear frequency
converters with arbitrary narrow spectral and thermal bandwidth, and finally
for structured illumination microscopy.


Ido Kanter, Bar-Ilan University

Neurons are the computational elements that compose the brain and their fundamental principles of activity are known for decades. According to the long-lasting computational scheme each neuron functions as a threshold unit. Each neuron sums the incoming electrical signals via its dendrites and when the membrane potential reaches a certain threshold the neuron typically generates a spike to its axon. We present three types of experiments, local and nonlocal time interference, using neuronal cultures, indicating that each neuron functions as a collection of independent threshold units, where the neuron is anisotropically activated following the origin of the arriving signals to the membrane.Finally, dendritic learning as a paradigm shift in brain learning will be briefly discussed. Results call to re-examine neuronal functionalities beyond the traditional framework, and the advanced computational capabilities and dynamical properties of such complex systems. 

- Dark matter revealed by the first stars? Rennan Barkana, Tel Aviv University
Rennan Barkana, Tel Aviv University

  The cosmic radio spectrum is expected to show a strong absorption signal around redshift 20 that corresponds to the rise of the first stars; specifically, the stellar radiation turns on 21-cm absorption by atomic hydrogen. The EDGES global 21-cm experiment has detected the first such signal, finding a stronger absorption than the maximum expected. This absorption can be explained by invoking excess cooling of the cosmic gas induced by an interaction with dark matter. This would have far reaching consequences, including an upper limit on the mass of dark matter particles that conflicts with the expectations for WIMPs. Specific particle physics models are highly constrained, but observations will decide. In particular, we predict that 21-cm fluctuations at cosmic dawn could be much larger than previously expected, exhibiting a specific signature of dark matter.

Using Supervised Machine Learning to Extract the Entanglement Entropy for a Quantum Many-Particle System Richard Berkovits, Dept. of Physics, Bar-Ilan University
Richard Berkovits, Dept. of Physics, Bar-Ilan University

Entanglement, which expresses non-local correlations in quantum mechanics, is the fascinating concept behind much of toady`s aspiration towards quantum technologies. Nevertheless, directly measuring the entanglement of a manyparticle system is very challenging. We shall present a proposal to use an artificial intelligence system based on supervised machine learning by a convolution neural network (CNN) to infer the entanglement from a measurable observable for a disordered interacting quantum many-particle system. Several structures of neural networks are tested and a deep CNN akin to structures used for image and speech recognition will be shown the best performance. After training on a set of 500 realizations of disorder, the network is applied on 200 new realizations and its results for the entanglement entropy (EE) where compared to a direct calculation of the EE. Excellent agreement was found, except for several rare region which in a previous study were identified as belonging to an inclusion of a different quantum phase associated with the Griffiths phase.

Recovering lost information in the digital world Yonina Eldar, Faculty of Electrical Engineering, the Technion
Yonina Eldar, Faculty of Electrical Engineering, the Technion
The conversion of physical analog signals to the digital domain for further processing inevitably entails loss of information.
The famous Shannon-Nyquist theorem has become a landmark in analog to digital conversion and the development of digital signal processing  algorithms. However, in many modern applications, the signal bandwidths have increased tremendously, while the acquisition capabilities have not scaled sufficiently fast. Furthermore, the resulting high rate digital data requires storage, communication and processing at very high rates which is computationally expensive and requires large amounts of power. 
In this talk, we present a framework for sampling and processing a wide class of wideband analog signals at rates far below Nyquist by exploiting signal structure and the processing task. We then show how these ideas can be used to overcome fundamental resolution limits in optical microscopy, ultrasound imaging and more. We demonstrate the theory through several demos of real-time sub-Nyquist prototypes and devices operating beyond the standard resolution limits combining high spatial resolution with short integration time.
How does life interact with light Yoni Toker
Yoni Toker

Most of the organic molecules, the basic building blocks of life, are transparent to visible light, except for a small group of molecules known as biochromophores. Biochromphores are responsible for vision, photo-synthesis (the process of harvesting solar energy), for exotic phenomena such as bioluminescense (for example in fireflies and jelly-fish) and for all the colors we see in nature. In this talk we will explore how tools developed originally for the study of nuclear and atomic physics provide an insight into the workings of these important molecules, and the basic quantum mechanical principles governing their behavior.

We will focus on the case of the retinal chromophore, which is the photon detector used in every known form of animal vision. We will show how the color of the chromophore can be tuned by its surrounding environment, which is critical for color vision. We will also discuss how to directly observe structural changes of the retinal chromophore using ion mobility spectroscopy.

Hyperpolarization with NV centers in diamond Alex Retzker, Racah Institute of Physics, Hebrew University in Jerusalem
Alex Retzker, Racah Institute of Physics, Hebrew University in Jerusalem

Efficient polarization of organic molecules is of extraordinary relevance when performing nuclear magnetic resonance (NMR) and imaging. Commercially available routes to dynamical nuclear polarization (DNP) work at extremely low temperatures, relying on the solidification of organic samples and thus bringing the molecules out of their ambient thermal conditions. In this talk I will review recent results of polarization transfer from optically pumped nitrogen vacancy centers in diamond to external molecules at room temperature.  These results set the route to hyperpolarization of diffusive molecules in different scenarios and consequently, due to an increased signal, to high-resolution NMR and MRI.

Nature's optics and our understanding of light Michael Berry, University of Bristol, UK
Michael Berry, University of Bristol, UK

Optical phenomena visible to everyone abundantly illustrate important

ideas in science and mathematics. The phenomena considered include

rainbows, sparkling reflections on water, green flashes, earthlight on the

moon, glories, daylight, crystals, and the squint moon. The concepts

include refraction, wave interference, numerical experimen,

asymptotics, Regge poles, polarization singularities, conical intersections,

and visual illusions.

Quantifying Hidden Order Out of Equilibrium Dov Levine, Faculty of Physics, Technion
Dov Levine, Faculty of Physics, Technion

While the equilibrium properties, states, and phase transitions of interacting systems are well described by statistical mechanics, the lack of suitable state parameters has hindered the understanding of non-equilibrium phenomena in divers settings, from glasses to driven systems to biology. Here we introduce a simple idea which enables the quantification of organization in non-equilibrium and equilibrium systems, even when the form of order is unknown. The length of a losslessly compressed data file is a direct measure of its information content, I, which, when the file represents a microstate in equilibrium, is its entropy. I will discuss Ifor some out-of-equilibrium systems, and show that it both identifies ordering and reveals critical behavior in dynamical phase transitions. 

Quantum Hall Edges: No End of Surprises Ganpathy Murthy, Dept. of Physics and Astronomy, University of Kentucky
Ganpathy Murthy, Dept. of Physics and Astronomy, University of Kentucky

Quantum Hall systems are the simplest examples of topological insulators. The bulk of a quantum Hall system has a gap to all charged excitations, and all charge conduction occurs at the edges. Typically, these edges are chiral, they carry current only in one direction. In real samples, as the confining potential at the edge is softened, the edges can undergo reconstruction, which means the number and chirality of the edge modes can change, despite the bulk being inert. I will discuss the general phenomenon of reconstruction, which is driven by electrostatic considerations, and end with an example of a novel type of reconstruction in which exchange, rather than electrostatics, plays the dominant role.

Gravity and Geometrization of Turbulence Yaron Oz, School of Physics & Astronomy, Tel-Aviv University
Yaron Oz, School of Physics & Astronomy, Tel-Aviv University
Fully developed incompressible fluid turbulence is largely considered as the most important unsolved problem of classical physics.
Most fluid motions in nature at all scales are turbulent, yet despite centuries of research, we still lack an analytical description and understanding of fluid flows in the non-linear regime. Experimental and numerical data suggest that turbulence at the inertial range of scales reaches a steady state that exhibits statistical homogeneity and isotropy and is characterized by universal scaling exponents. We will propose a conceptually new viewpoint inspired by black hole dynamics and construct a field theory geometrization of turbulence.  Within this framework we will derive an exact analytical formula for the inertial range longitudinal  anomalous scalings in agreement with the available numerical and experimental data. We will present new predictions of the formula.
Light-Matter Interaction in Quantum Photonic Nanostructures Eli Kapon, Institute of Physics, EPFL, Switzerland
Eli Kapon, Institute of Physics, EPFL, Switzerland

See attached

Could we be missing new physics at the LHC? Shikma Bressler, Dept. of Particle Physics & Astrophysics, Weizmann Institute
Shikma Bressler, Dept. of Particle Physics & Astrophysics, Weizmann Institute

Despite its great success in describing the elementary particles and interactions among them, the Standard Model (SM) fails to explain certain phenomena: it does not include gravity, it accommodates neither neutrino masses nor dark matter, and it predicts a minuscule baryon asymmetry. These shortcomings indicate that the SM needs to be extended. Many models extending the SM have been developed over the years and the search for signatures predicted by these models is at the core of the physics program of two of the LHC experiments, ATLAS and CMS, at CERN. 

So far, after over seven years of data taking, no indication for physics beyond the SM (BSM) was observed. Could we be missing something? In this talk, I will review some of the main actions we take in order to guarantee that if BSM physics is produced at the LHC it will not escape detection.

Dark Matter detection - current front and the future Ran Budnik, Dept. of Particle Physics & Astrophysics, Weizmann Institute
Ran Budnik, Dept. of Particle Physics & Astrophysics, Weizmann Institute

Dark matter has been a major paradigm in cosmology for the past five decades, with evidence mounting and becoming ever more convincing over the years. However, all the observations of this elusive matter are based on gravitational systems. Many efforts to determine the particle or field nature of the dark matter were carried out, but so far without success. In my talk I will go through the evidence and basic notions related to dark matter, and will then focus on one of the most promising channels for its understanding - direct searches for dark matter. I will present the current state of affairs, with the world's most sensitive detector, XENON1T, and then discuss the future of the filed, with planned experiments and small scale R&D.

The Magic Scale of Galaxies Avishai Dekel, Hebrew University of Jerusalem
Avishai Dekel, Hebrew University of Jerusalem

This talk will address the preferred mass and time for galaxy formation, in dark-matter haloes similar to the one that hosts the Milky way but when the Universe was only a few Gigayears old. It is proposed that this magic scale arises from the interplay between supernova explosions in low-mass galaxies and feedback from super-massive black holes in massive galaxies, associated with shock heating of the circum-galactic gas which suppresses cold gas supply for star formation in massive galaxies. Cosmological simulations reveal that the same mechanisms are responsible for a robust sequence of events in the history of typical galaxies, were galaxies undergo a dramatic gaseous compaction, sometimes caused by galaxy mergers, into a compact star-forming phase, termed “blue nugget”. This process triggers inside-out quenching of star formation, which is maintained by a hot massive halo aided by black-hole feedback, leading to todays passive elliptical galaxies. The blue-nugget phase is responsible for drastic transitions in the main galaxy structural, kinematic and compositional properties. In particular, the growth of the black hole in the galaxy center, first suppressed by supernova feedback when below the critical mass, is boosted by the compaction event and keeps growing once the halo is massive enough to lock the supernova ejecta by its deep potential well and the hot halo. These events all occur near the same characteristic halo mass, giving rise to the highest efficiency of galaxy formation and black-hole growth at this magic mass and time.

Nonlinear X-Ray Spectroscopy Sharon Shwartz, Bar Ilan University
Sharon Shwartz, Bar Ilan University

Ordinary nonlinear optical processes in x-ray regime are known to be very weak, while conventional x-ray sources suffer from insufficient brightness. Nevertheless, recent and expected improvements in brightness and beam quality of x-ray sources, together with new facilities such as the x-ray free-electron laser, offer the possibility of extending the concepts of nonlinear and quantum optics into x-ray energies. The new facilities with their increased power allow the observation of new x-ray nonlinear and quantum effects. Indeed, recently, the number of demonstrations of nonlinear and quantum effects in the x-ray regime, is growing rapidly. I will describe recently performed and proposed nonlinear experiments at x-ray wavelengths including x-ray and visible wave mixing [1], x-ray second harmonic generation [2] and x-ray parametric down-conversion into the ultraviolet and optical regimes [3,4]. I will discuss future directions of implementing nonlinear x-ray techniques as tools for spectroscopy and studies of ultrafast effects. For example, x-ray and visible mixing may lead to atomic scale resolution techniques to study chemical bonds. X-ray parametric down-conversion can be developed into techniques to study properties such as Fermi energies, plasmons, and the density of states in crystals. Nonlinear techniques are expected to be useful in the inspection of subfemtosecond temporal pulses.

[1] T. E. Glover et al. Nature 488, 603 (2012).

[2] S. Shwartz et al. Phys Rev. Lett. 112, 163901 (2014)

[3] D. Borodin , S. Levy , and S. Shwartz, App. Phys. Lett. 110, 131101 (2017).

[4] A. Schori et al. Phys. Rev. Lett. 119, 253902 (2017)

Ultra-fast rogue waves Moti Fridman, Bar Ilan University
Moti Fridman, Bar Ilan University

Rogue waves are frick waves suddenly appearing and can endanger life and cargo. For many years no one believed that such waves exist and any stories about it were considered as fairy tales. Recently, such waves were discovered in different mediums and specifically in optics. We discovered a new type of rogue waves and measured it with high resolution. In the talk, we will present the mechanism behind rogue waves in general and specifically our type of rogue waves.   

- An information machine with tunable correlations based on colloid particle diffusion Yael Roichman, Tel Aviv University
Yael Roichman, Tel Aviv University

We realize experimentally an information machine converting information to work. Our experimental design is comprised of a colloidal particle diffusing in a microfluidic channel, with a repelling laser based barrier that is moved in feedback to the measured particle position. In a quasi-static mode of operation, the amount of used information is related to the Shannon entropy of uncorrelated steps. We develop a scheme to calculate this information at steady state at fast operation, which induces temporal correlations. We use this calculation to characterize the output power and efficiency of our information machine as a function of feedback cycle time.

Adi Natan from Stanford

Realizing imaging of atomic motion de-novo within multiple molecular bonds in isolated molecules, with Angstrom and femtosecond resolutions is a grand challenge for the atomic molecular and optical physics community.  We will present several recent results in imaging quantum dynamics at the atomic length and time scales using ultrafast coherent x-ray diffraction at free electron lasers, photoelectron self-diffraction via strong field ionization, coincidence techniques, and advanced imaging and data analysis schemes that create such molecular movies without prior information of the system under study.  Time-resolved femtosecond x-ray diffraction patterns from laser-excited molecular iodine were used to create high fidelity molecular movies de-novo. We imaged electronic population transfer, vibrational motion, dissociation, rotational dephasing, Raman transitions, and non-adiabatic population transfer via coherent mixing of different electronic states.  We’ll also discuss results from photoelectron velocity map imaging and coincidence techniques as potential routes for table-top molecular movies. Finally, we will discuss using novel experimental and analysis methods, extending to the condensed phase and to systems of increased complexity.

Observing a Scale Anomaly in Graphene : a Universal Quantum Phase Eric Akkermans, Faculty of Physics, Technion
Eric Akkermans, Faculty of Physics, Technion

Scale invariance is a common property of our everyday environment. Its
breaking gives rise to less common but beautiful structures like fractals.
At the quantum level, breaking of continuous scale invariance is a
remarkable exemple of quantum phase transition also known as scale
anomaly. The general features of this transition will be presented at an
elementary quantum mechanics level. Then, we will show recent experimental
evidence of this transition in graphene.

Frontiers in the study Gamma-ray bursts Asaf Pe'er, Physics Department, University College Cork (UCC), Ireland
Asaf Pe'er, Physics Department, University College Cork (UCC), Ireland
Gamma ray bursts (GRBs) are the most violent explosions in the
universe. While being studied extensively since the 1990's, a major
event took place a few weeks ago, with the first confirmed detection
of a GRB associated with the gravitational wave (GW) signal that
results from the merger of binary neutron star (NS) system, namely
In the first part of the talk I will give broad overview of our
current understanding of GRB physics, followed by a description of the
GW/GRB170817a event and its implications.
In the second part of the talk (as time permits), I will discuss the
recent development in undertsanding the origin of the prompt spectra,
and in particular the role of thermal emission in it.  I will discuss
some novel effects and theoretical ideas relevant for the study of
many astronomical objects. As a few examples, I will show how emission
from the photosphere can be observed to have high degree of
polarization; how it can be used to infer the jet magnetization; and
The LHC search for the physics behind the Standard Model Yevgeny Kats, Department of Physics, Ben-Gurion University
Yevgeny Kats, Department of Physics, Ben-Gurion University

I will start with an overview of some of the most important open
questions in particle physics. Some of these issues require, and other
strongly suggest, the existence of yet-unknown particles and fields in
nature. I will argue that the Standard Model is just an effective
partial description of a more fundamental theory that stands behind it
and is yet to be discovered. I will then focus on the puzzle of the
electroweak-Planck hierarchy, where hints about the underlying
mechanism are likely to be within the reach of the Large Hadron
Collider (LHC) at CERN. I will also mention my own work, which
involves analyzing the results of LHC searches and proposing new
search directions for the physics behind the electroweak-Planck
hierarchy and other new phenomena that may be accessible at the LHC.

Neutrino masses go to Stockholm Yossi Nir, Department of Particle Physics and Astrophysics, Weizmann institute of science
Yossi Nir, Department of Particle Physics and Astrophysics, Weizmann institute of science

The Nobel Prize in Physics 2015 was given to the leaders of two experiments that discovered neutrino flavor transitions. This discovery shows that neutrinos have mass. I will describe the experiments and their results, and explain the implications for theory and their significance.

The Markovian Mpemba effect: weak, strong and inverse anomalous thermal relaxation Oren Raz, Dept. of Physics of Complex Systems, Weizmann Institute of Science
Oren Raz, Dept. of Physics of Complex Systems, Weizmann Institute of Science

Under certain conditions, it takes a shorter time to cool a hot system than to cool the same system initiated at a lower temperature. This phenomenon — the “Mpemba effect” — was first observed in water and has recently been reported in other systems. Whereas several detail-dependent explanations were suggested for some of these observations, no common underlying mechanism is known. We present a widely applicable mechanism for a similar effect, the Markovian Mpemba effect, derive the sufficient conditions for its appearance, and demonstrate it explicitly in the anti-ferromagnet Ising model. Interestingly, the Markovian Mpemba effect can be classified as ``weak'' or ``strong'' and as ``direct'' or ``inverse''. In the Ising model we show that the ``strong'' (direct and inverse) effect exists even in the thermodynamic limit.

Water and the Hydrophobic Interaction in X10,000,000 Magnification Uri Sivan, Dep. of Physics and the Russell Berrie Nanotechnology Institute – Technion
Uri Sivan, Dep. of Physics and the Russell Berrie Nanotechnology Institute – Technion

The governing role of hydrophobic interactions in countless biological phenomena and technological systems, including protein folding, transmembrane proteins, cell membranes, detergents, paints, decontamination of pollute water, and more, has motivated extensive theoretical and experimental efforts aimed at deciphering the microscopic foundations of this interaction. Yet, after more than a century of extensive research a full predictive theory of this elusive phenomenon is still missing, largely due to the lack of suitable experimental techniques capable of probing the interface between hydrophobic surfaces and water at high enough resolution. In the talk, I will present our recent explorations of this interface using an ultra-high resolution atomic force microscope built in-house for the task and disclose compelling evidence that the hydrophobic interaction reflects a phase transition taking place in the medium when two hydrophobic surfaces approach each other to within a few nanometers. Along the way I'll demonstrate the sub-atomic resolution of our microscope and its value for the study of water structure near surfaces and biomolecules.

The Interpretation of Quantum Theory: Copenhagen vs. Petach Tikva Nathan Aviezer, Dept. of Physics, BIU
Nathan Aviezer, Dept. of Physics, BIU

Quantum theory is the strangest theory ever introduced into science.  Everyone knows how to make calculations using quantum theory and the calculations always agree with experiment.  But questions remain regarding what this theory is telling us about nature.  This is called the “interpretation of quantum theory.”  The most widely accepted interpretation of quantum theory is the Copenhagen interpretation.  I will discuss the Copenhagen interpretation, point out its defects, and present an alternative interpretation which does not suffer from these defects.

Cosmic Rays and Climate: From Solar Forcing and 20th century climate change to Dark Matter in the Milky Way's disk Nir Shaviv, Racah Institute of Physics, Hebrew University
Nir Shaviv, Racah Institute of Physics, Hebrew University

Over the past 2 decades, our understanding of how cosmic rays affect the terrestrial cloud cover has evolved from rough empirical evidence to an almost complete physical picture. This link helps us understand many of the past climate variations—from days to Eons, including for example the appearance of ice age epochs on Earth and 20th century global warming. In this talk I will review the evidence including recent breakthroughs in our atmosphere mimicking lab, which pin point the two physical mechanisms increasing linking between atmospheric charge and the formation of cloud condensation nuclei. I will also discuss resent results on how the cosmic ray climate link can be used to determine the amount of Dark Matter at the galactic plane.

Levy walks in swarming bacteria Gil Ariel, Department of Mathematics, Bar-Ilan University
Gil Ariel, Department of Mathematics, Bar-Ilan University

Bacterial swarming is a collective mode of motion in which cells migrate rapidly over surfaces. Swarming is typically characterized by densely packed groups moving in coherent patterns of whirls and flows. Recent experiments showed that within such dense swarms, bacteria are performing super-diffusion that is consistent with a Levy walk. The talk will explain this observation and present a simple model suggesting that chaos and Levy walking are a consequence of group dynamics. The model explains how cells can fine-tune the geometric properties of their trajectories.

Proximity-induced triplet superconductivity in systems comprising ferromagnets, graphene and chiral-molecules Prof. Oded Millo, Racah Institute of Physics, The Hebrew University of Jerusalem
Prof. Oded Millo, Racah Institute of Physics, The Hebrew University of Jerusalem

In the vast majority of superconductors, the Cooper pairs are formed from electrons with an antiparallel spin alignment and are in the spin-singlet state. In contrast, there are very few materials that show evidence for the exotic state of triplet superconductivity, in which the Cooper pairs comprise electrons with parallel spins. Such a state was predicted to emerge, under some conditions, at superconductor-ferromagnet (S-F) interfaces, and may be important for superconducting-spintronic devices. First experimental evidence for triplet superconductivity was provided by observations of long-range (much larger than the coherence length in F) spin-polarized supercurrents in S-F-S devices. To address this problem from a different angle, we employed scanning tunneling spectroscopy (STS) on various S-F bilayer systems, and our tunneling spectra reveal long-range penetration of superconducting correlations into the ferromagnet, consistent with spin-aligned triplet-pairing with a p-wave order-parameter symmetry. I will also discuss two other systems that showed clear signatures of p-wave triplet-superconductivity in the tunneling spectra. The first consists of a-helix chiral molecules deposited on Nb (a conventional superconductor), and the second comprises single layer graphene deposited on the electron-doped cuprate superconductor Pr1.85Ce­CuO4.  


Dimensionality Matters: Dimensionality Effects on Optoelectronic Behavior of Semiconductor Nanocrystals Prof. Uri Banin, Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem
Prof. Uri Banin, Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem

Studying the transition of properties of nanostructures as they develop from the zero-dimensional to the one-dimensional regime is significant for unravelling the modifications that occur in the electronic structure of the particle as its length to width aspect ratio is increased. Such understanding can lead to better design and control of the particle properties, with relevance for a wide range of technological applications and in particular for flat panel displays, where semiconductor nanocrystals are presently used to achieve greatly improved color quality with energy saving characteristics. The high degree of control of shape and morphology of nanoparticles in colloidal synthesis, which allows forming structures of similar composition but of different dimensionalities and shapes, open the way for probing such dimensionality effects. We will present several effects involving the 0D to 1D transition in semiconductor nano heterostructures of different morphologies including “sphere in a sphere”, “sphere in a rod” and “rod in a rod”. Further effects of a graded shell composition, a novel rod-couples architecture and dumbbells morphology will also be described. 

Biological systems as complex dynamical networks Dr. Amir Bashan, Physics Department, Bar-Ilan University
Dr. Amir Bashan, Physics Department, Bar-Ilan University

Many real-world complex systems are composed of interacting entities, where their measured activity is a result of underlying complex, usually nonlinear, dynamics. Examples of such network-based dynamical models include: biochemical, ecological and regulatory dynamics. Understanding the underlying dynamics is a key in order to control those systems. Indeed, theory of nonlinear dynamics in mathematics and statistical physics provide deep and detailed understanding of such systems. Yet, the main challenge is that most of the available data comes from snapshots originated in different individuals, and thus is considered as insufficient to extract the actual underlying dynamics, which remain unknown. I will present a novel approach to address this gap between the theory of nonlinear dynamics and the available data from dynamical systems. The approach will be demonstrated on two systems: (i) the human microbiome, the ecological community of microbes living in and on our body, and (ii) gene regulatory networks in human cells. 

Negative resistance, super-ballistic conductance and other wonders of viscous electronics Gregory Falkovich, Department of Physics of Complex Systems, Weizmann Institute of Science
Gregory Falkovich, Department of Physics of Complex Systems, Weizmann Institute of Science

Quantum-critical strongly correlated systems feature universal collision-dominated collective transport. Viscous electronics is an emerging field dealing with systems in which strongly interacting electrons flow like a fluid. We identified vorticity as a macroscopic signature of electron viscosity and linked it with a striking macroscopic DC transport behavior: viscous friction can drive electric current against an applied field, resulting in a negative resistance, recently measured experimentally in graphene. I shall also describe current vortices, expulsion of electric field, conductance exceeding the fundamental quantum-ballistic limit and other wonders of viscous electronics. Strongly interacting electron-hole plasma in high-mobility graphene affords a unique link between quantum-critical electron transport and the wealth of fluid mechanics phenomena.

Molecular quantum conductors: charge and spin transport manipulations by interface effects and reduced dimensionality Oren Tal, Department of Chemical Physics, Weizmann Institute of Science
Oren Tal, Department of Chemical Physics, Weizmann Institute of Science

The inherent electronic mismatch between molecules and metals is a general limitation for efficient electron transport in molecule-based electronics, including organic light emitting diodes, nanoscale organic spin-valves, and single-molecule transistors.

In this talk, I will review our recent progress in revealing an upper limit for conductance across metal-single molecule interfaces [1], as well as extreme spin filtering and unusual magneto-transport effects in metal-oxide junctions [2] and half-metallic molecular junctions. These findings can be used to derive general principles for efficient charge and spin transport manipulations at the atomic scale [1-4].


[1] T. Yelin, R. Korytár, N. Sukenik, R. Vardimon, B. Kumar, C. Nuckolls, F. Evers & O. Tal, Nature Materials, 15, 444 (2016).      

[2] R. Vardimon, M. Klionsky & O Tal, Nano Letters, 15, 3894 (2015).

[3] D. Rakhmilevitch, R. Korytár, A. Bagrets, F. Evers & O. Tal, Physical Review Letters 113, 236603 (2014).

[4] D. Rakhmilevitch, S. Sarkar, O. Bitton, L. Kronik & O. Tal, Nano Letters 16, 1741 (2016).


Cascading Failures and Recovery in Interacting Networks Shlomo Havlin, Physics Department, Bar-Ilan University
Shlomo Havlin, Physics Department, Bar-Ilan University

A framework for studying the vulnerability and the recovery of networks of interdependent networks will be presented.

 In interdependent networks, when nodes in one network fail, they cause dependent nodes in other networks to also fail. 

This may happen recursively and can lead to a cascade of failures and to a sudden fragmentation of the system.
I will present analytical solutions for the critical thresholds and the giant component of a network of n interdependent networks.   I will present examples of applying our model to real  interacting networks.

I will also show, that the general theory has many novel features that are not present in the classical network theory. 

When recovery of components is enabled, global spontaneous recovery of the networks and hysteresis phenomena occur

 and the theory suggests an optimal repairing strategy for a system of systems.
I will also show that interdependent networks embedded in space are
significantly more vulnerable compared to non embedded networks. In particular, small localized attacks of zero fraction 

may lead to cascading failures and catastrophic consequences.

Thus, analyzing real data and realistic models of network of networks is highly required to understand the system vulnerability.

[1] J. Gao, S. Buldyrev, H. E. Stanley, S. Havlin, Nature Physics, 8, 40 (2012).
[2] A. Bashan et al, Nature Physics, 9, 667 (2013)
[3] A Majdandzic et al, Nature Physics 10 (1), 34 (2014); Nature Comm. 7, 10850 (2016)

[4] Daqing Li, B. Fu, Y. Wang, G. Lu, Y. Berezin, H. E. Stanley, S. Havlin, PNAS 112, 669 (2015)

[5]  J. Zhao, Daqing Li, H. Sanhedrai, R. Cohen, S. Havlin, Nature Comm. 7, 10094 (2016)  

Coherent quantum phenomena in superconducting atomic monolayers Pb/Si(111): A STM study Dimitri Roditchev - INSP, CNRS & Sorbonne University
Dimitri Roditchev - INSP, CNRS & Sorbonne University


In 1964 V. L. Ginzburg predicted that new superconducting phases could appear in ultrathin films deposited on insulating surfaces. In 2010 superconductivity below 2K was discovered in some crystalline atomic monolayers of Pb grown on atomically clean Si(111) [1, 2]. Though, the amorphous Pb monolayer was found non-superconducting, but rather a correlated metal. Interestingly, Pb-monolayers can be on-demand made amorphous or crystalline, with or without presence of bulky superconducting Pb-nano-islands. This makes the Pb/Si(111) system useful to probe superconducting correlations in the vicinity of S-N or S-S’ interfaces by STM [3,4].

When two superconducting Pb-islands are linked together by a few nanometer wide non-superconducting amorphous atomic layer of Pb, superconducting correlations may propagate between the two islands, allowing a dissipation-less Josephson current to flow through the link. In the presence of a magnetic field, the Josephson vortices are expected to appear in such S-N-S Josephson junction. Josephson vortices are conceptual blocks of advanced quantum devices such as coherent terahertz generators or qubits for quantum computing, in which on-demand generation and control is crucial.

In our lecture we describe a series of recent experiments which mapped superconducting correlations in the vicinity of S-N junctions [3,4] as well as inside SNS proximity Josephson junctions using scanning tunneling microscopy [5]. By following the Josephson vortex formation and evolution we demonstrate that they originate from quantum interference of Andreev quasiparticles, and that the phase portraits of the two superconducting quantum condensates at edges of the junction decide their generation, shape, spatial extent and arrangement [5].


[1] T. Zhang, et al. Nature Phys. 6, 104–108 (2010).

[2] Ch. Brun, et al. Nature Phys. 10, 444 (2014).

[3] L. Serrier-Garcia, et al. Phys. Rev. Lett. 110, 157003 (2013).

[4]V.Cherkez, et al. Phys. Rev. X 4, 011033 (2014).

[5] Roditchev D., et al. Nature Phys. 11, 332 (2015).

Friction is Fracture: a new paradigm for the onset of frictional motion Jay Fineberg, The Racah Institute of Physics, The Hebrew University, Jerusalem
Jay Fineberg, The Racah Institute of Physics, The Hebrew University, Jerusalem

Friction is generally described by a single degree of freedom, a ‘friction coefficient’. We experimentally study the space-time dynamics of the onset of dry and lubricated frictional motion when two contacting bodies start to slide. We first show that the transition from static to dynamic sliding is governed by rupture fronts (closely analogous to earthquakes) that break the contacts along the interface separating the two bodies. Moreover, the structure of these "laboratory earthquakes" is quantitatively described by singular solutions originally derived to describe the motion of rapid cracks under applied shear. We demonstrate that this framework quantitatively describes both earthquake motion and arrest. A further surprise is that lubricated interfaces, although “slippery”,  actually becomes tougher; lubricants significantly increase dissipated energy during rupture. The results establish a new (and fruitful) paradigm for describing friction.

Hydra regeneration: a window on morphogenesis Erez Braun, Physics, Technion
Erez Braun, Physics, Technion

Morphogenesis, the emergence of well-defined patterns of functional tissues during development, is carried out by the collective dynamics of multiple physical and biochemical processes at different levels of organization, from local molecular events to large-scale chemical, electrical and mechanical stress fields. Morphogenesis emerges by the interaction of these various processes, which must evolve simultaneously as coupled fields. We take advantage of a unique multicellular organism, Hydra, famous for its extraordinary regeneration capabilities, to advance our biophysical understanding of morphogenesis. I will discuss our recent experiments on Hydra regeneration, shedding light on the role of the actomyosin cytoskeleton and the forces it generates during morphogenesis. We apply mechanical constraints by studying regeneration from tissue segments anchored on wires, showing that the wires induce order in morphogenesis. Finally, we utilize external force fields, hydrodynamic flows, electric fields and magnetic forces on beads attached to the regenerating tissue, to induce spatio-temporal modes during the regeneration process. Perturbing the regeneration process and imposing external constraints enable us to expose alternative developmental trajectories.

Chirality and spin- The Chiral Induced Spin Selectivity Effect Ron Naaman, Department of Chemical Physics, Weizmann Institute
Ron Naaman, Department of Chemical Physics, Weizmann Institute

Spin based properties, applications, and devices are commonly related to magnetic effects and to magnetic materials. However, we found that chiral organic molecules act as spin filters for photoelectrons transmission [1]  in electron transfer [2] and in electron transport [3]  .

The new effect, termed Chiral Induced Spin Selectivity (CISS) [4,5]  has interesting implications for the production of new types of spintronics devices [6]  and on electron transfer in biological systems.  The effect was found in bio-molecules and in bio-systems [7]. The basic effect will be explained and various applications and implications will be discussed.


  1. Göhler, B.; Hamelbeck, V.; Markus, T.Z.; Kettner, M.; Hanne, G.F.; Vager, Z.; Naaman, R.; Zacharias,  H. Science 2011, 331, 894.
  2. Mishra, D.; Markus, T.Z.; Naaman, R.; Kettner, M.; Göhler, B.; Zacharias, H.; Friedman, N.; Sheves, M.; Fontanesi, C. PNAS,   2013, 110, 14872.
  3.  Xie, Z.; Markus, T. Z.; Cohen, S. R.; Vager, Z.; Gutierrez, R.; Naaman, R. Nano Letters, 2011, 11, 4652.
  4. Naaman, R.; Waldeck, D.H. J. Phys. Chem. Lett. (feature) 2012, 3, 2178.
  5. R. Naaman, D. H. Waldeck, Spintronics and Chirality: Spin Selectivity in Electron Transport Through Chiral Molecules, Ann. Rev. Phys. Chem. 2015, 66, 263–81.
  6. Ben Dor, O.; Yochelis, S.; Mathew, S. P.; Naaman, R.; Paltiel, Y. Nature Communication, 2013, 4, 2256.
  7.  I. Carmeli, K. S. Kumar, O. Hieflero, C. Carmeli, R. Naaman,  Angew. Chemie  2014, 53, 8953 –8958.
Factorization and Universality in Nuclear Physics Nir Barnea, The Racah Institute of Physics, The Hebrew University, Jerusalem
Nir Barnea, The Racah Institute of Physics, The Hebrew University, Jerusalem

Few years ago it was suggested by S. Tan that the properties of cold and dilute quantum gases depend on a new characteristic quantity, the ``contact''. The ``contact'' describes the probability of two particles coming close to each other, i.e. it is a measure of the number of close particle pairs in the system. Utilizing this concept, a series of theorems, already verified experimentally, predicts the macroscopic properties of the system. In my talk I will present Tan’s  ``contact'' and its generalization to nuclear systems, introducing the various nuclear contacts, and their applications.

Mass Transfer in Binaries: Planets Around Stars and Stars Around Supermassive Black Holes Re'em Sari, The Racah Institute of Physics, The Hebrew University, Jerusalem
Re'em Sari, The Racah Institute of Physics, The Hebrew University, Jerusalem

Mass transfer between members of a binary is a common and well studies situation. As members of a binary become closer to each other, mass may leak from one object due to the strong tidal forces from the other. Usually, the leaking mass flows towards the companion, but we show that for main sequence stars that orbit the supermassive black hole in the galactic center and emit gravitational waves mass may also leak away from it. We show that the mass transfer affects the evolution of the gravitational wave emission in a way that reflects internal properties of the star. This may be relevant to observations of the planned LISA mission. On another front, tides may lead to orbital decay of planets which are close enough to their stars. Mass transfer will occur and we discuss its observational consequences in view of data from the Kepler mission.

חומרי הדברה בחקלאות לבטים ופתרונות – החיטוי הסולרי כמשל יעקב קטן, המחלקה למחלות צמחים ומיקרוביולוגיה, האוניברסיטה העברית, הפקולטה לחקלאות, מזון וסביבה, רחובות
יעקב קטן, המחלקה למחלות צמחים ומיקרוביולוגיה, האוניברסיטה העברית, הפקולטה לחקלאות, מזון וסביבה, רחובות

גורמי מחלות (פתוגנים), מזיקים ועשבים גורמים נזקים רבים לגידולים חקלאיים והם פוגעים ביכולתנו לספק מזון בעולם שאוכלוסייתו גדולה ואשר בו יותר מ-800 מליון רעבים. הדברת גורמי הפגע מאפשרת העלאת היבולים. השימוש בחומרי הדברה (pesticides) הוא דרך מאוד יעילה להדברת הפגעים הללו אך השימוש בהם עלול לפגוע בסביבה ובבריאות. נעשים מאמצים לפתח  חלופות לחומרי הדברה שהן ידידותיות לסביבה אך גם יעילות בהדברה. פיתוח זני צמחים עמידים גנטית למחלות, הדברה ביולוגיות של פגעים ושיטות אחרות הנן חלופות שנחקרות וחלקן בשימוש נרחב.

בארץ פותחה שיטת החיטוי הסולרי (Soil solarization) של חימום הקרקע באמצעות יריעות פוליאתילן שקופות להדברה פתוגנים ועשבים ע"י קטילה תרמלית של הפתוגנים כחלופה לחיטוי כימי של הקרקע אשר נעשה בדרך כלל באמצעות חומרים רעילים. נערכו מחקרים רבים בארץ ובעולם (ביותר מ-70 מדינות) על היבטים מיקרוביאליים, פיסיקליים, כימיים, אגרוטכניים, טכנולוגיים, כלכליים ועוד של החיטוי הסולרי במטרה לשפר את יעילותו ולהרחיב את השימוש בו למטרות נוספות, מעבר לחיטוי קרקע.

שימו לב: ההרצאה תנתן בעברית. המרצה - חתן פרס ישראל בחקר החקלאות ומדעי הסביבה משנת תשע"ד.

Waves, vortices and superfluids Frédéric Chevy, École Normale Supéuriere, Paris, France
Frédéric Chevy, École Normale Supéuriere, Paris, France

In his famous lectures, R. P. Feynman highlights the deep unity of physics and the analogies existing between sometimes vastly different physical systems. In the same spirit I will demonstrate how the tools and concepts inherited from classical hydrodynamics can be used to explain the quantum world. As an example, I will show that the same phenomena govern the physics of water-walking insects and that of laser-cooled superfluid vapours.

New frontiers in Attosecond Science Nirit Dudovich, Department of Physics of Complex Systems, Weizmann Institute of Science
Nirit Dudovich, Department of Physics of Complex Systems, Weizmann Institute of Science

Attosecond science is a young field of research that has rapidly evolved over the past decade. Performing time-resolved measurements with attosecond precision is a significant challenge. The rapid progress in this field opened a door into a new area of research that allows one to observe multi-electron dynamics. Currently, two main approaches have been successfully demonstrated. The first approach, Attosecond Pump-Probe Spectroscopy, applies an attosecond pulse to initiate or probe a fast-evolving process. An alternative approach, Attosecond Self-Imaging, applies the attosecond production process, to perform the measurement.

Although attosecond spectroscopy holds great promise for both measurement and control of matter, the understanding and implementation of most processes pose significant challenges. The extreme nonlinear nature of the interaction offers numerous channels, strongly coupled by the strong laser field, in which electronic dynamics can evolve.

In the talk I will review some of the main challenges and goals in the field of attosecond science. I will describe advanced schemes in attosecond spectroscopy where the interaction is probed via several synchronized fields. Such integration probes the multidimensional nature of the interaction, thus revealing its complexity. I will then focus on a new direction that integrates the two main branches in attosecond spectroscopy – the attosecond pump-probe scheme with the self-imaging approach.  This scheme increases the dimensionality in both the measurement and control of attosecond scale processes, allowing the observation of a wide range of multielectron phenomena.

Prof. Nathalie Q. Balaban

Noise analysis in biological systems has greatly increased our understanding of the underlyingcellular processes. Noise in the cell division process is often assumed to be responsible for variability in cell cycle duration, and to underlie heterogeneous responses of bacteria to antibiotics, as well as of cancer cells to drugs.

We show that variability of growth in bacteria can evolve under fluctuating environment.  

More generally, we ask whether we can differentiate between stochastic and deterministic control of cell division variability. Using long-term time lapse microscopy to follow thousands of divisions and tools from non linear dynamics analysis, we show that the variability in cell-cycle duration in mammalian cells, which at first glance seems dominated by noise, is in fact controlled by a deterministic factor.


Prof. Ady Stern

In this talk I will review the concept of topological superconductivity, of the associated Majorana fermions, and of their recent realization using nanowires in proximity to conventional superconductors. I will then analyze the way that two dimensional Josephson junctions may be employed to create one dimensional topological superconductors and describe the unique properties of the resulting system. 

Transport in Strongly Correlated Bad Metals Prof. Aharon Kapitulnik
Prof. Aharon Kapitulnik

The standard paradigm for transport in metals relies on the existence of quasiparticles. Transport coefficients such as electrical and thermal conductivities can then be calculated using e.g. Boltzmann equations. However, such an approach fails in the so-called `bad metal' regime, when the quasiparticle mean free paths become comparable to the wavelengths of the electron and/or highest frequency phonon. Transport in non-quasiparticle regimes requires a new framework and has become a subject of intense theoretical and experimental efforts in recent years.  In particular, the diffusivity was singled out as a key observable for incoherent non-quasiparticle transport, possibly subject to fundamental quantum mechanical bounds. Following a review of previous experimental results on bad metallic behavior, we will introduce new results on transport in strongly correlated electron systems with strong electron-phonon interaction. These results suggest that when neither well-defined electron nor phonon quasiparticles are present, thermal transport exhibits a collective behavior of a `soup' of strongly coupled electrons and phonons which diffuses at a unique velocity, exhibiting a saturated scattering time of ~ħ/kT.


Gravitational waves, GW150914 and compact binary mergers Tsvi Piran, Racah Institute for Phyiscs, The Hebrew University, Jerusalem
Tsvi Piran, Racah Institute for Phyiscs, The Hebrew University, Jerusalem

Gravitational waves were predicted by Albert Einstein as an outcome of the general theory of relativity in 1916. Advanced LIGO was barely switched on when the frist gravitational radiation signal ever, GW 150914, was detected. It turned out that it signaled a merger between two ~30 solar masses black holes some 1.5 billion light years away. Later on a second signal, GW 151226, was detected. I will review the physics of gravitational radiation, the advanced LIGO detector, these recent discoveries and their various implications.

Faceting of tailed liquid droplets: the role of topological defects Prof. Eli Sloutskin, Physics Departement, Bar Ilan
Prof. Eli Sloutskin, Physics Departement, Bar Ilan

Among all possible shapes of a volume V, a sphere has the smallest surface area A. Therefore, liquid droplets are spherical, minimizing their interfacial energy \gamma A for a given interfacial tension \gamma. We demonstrate that liquid oil droplets in water, stabilized by a common surfactant, adopt icosahedral and other faceted shapes, tunable by temperature, while still remaining liquid[1,2]. Although liquid droplets have been studied for centuries, no faceted droplets have ever been detected.

We attribute the observed transition from a spherical to an icosahedral shape to the interplay between \gamma and the elastic properties of the interfacial monomolecular layer, which in these systems crystallizes above the bulk melting point. The role of topological lattice defects in this quasi-two-dimensional crystalline surface monolayer will be discussed. The shape of the droplets is determined by the topological charge of these defects (i.e., the number of nearest neighbours missing at each defect), with the icosahedral droplets transforming on cooling into platelet-like rectangular, hexagonal, hexagram-like and other faceted shapes. In addition to faceting, we observe a wide range of other unexpected phenomena, such as a spontaneous splitting of liquid droplets. The common physical mechanism, responsible for all these effects will be demonstrated[1,2].

These phenomena allow deeper insights into the fundamentals of molecular elasticity to be gained, mimicking faceting transitions in complex biological systems and opening new horizons for a wide range of technologies, from self-assembly of complex colloidal shapes to new delivery strategies in bio-medicine.

[1] S. Guttman, Z. Sapir, M. Schultz, A. V. Butenko, B. M. Ocko, M. Deutsch, and E. Sloutskin,
Proc. Natl. Acad. Sci. USA 113, 493 (2016).

[2] S. Guttman, B. M. Ocko, M. Deutsch, and E. Sloutskin, Curr. Opin. Colloid Interface Sci. 22, 35 (2016).

Predicting Wave localization in Complex Structures from a Static Measurement Prof. Patrick Sebbah, Physics Department, Bar Ilan
Prof. Patrick Sebbah, Physics Department, Bar Ilan

Predicting the spatial pattern of vibrational modes in complex systems remains a key scientific and engineering challenge with strong repercussions in various domains such as laser cavity design or musical instrument architecture. A recent theoretical breakthrough brings a new tool, called the "localization landscape", for retrieving crucial information on the spatial and frequency properties of these localized waves [1].

Here, this theory is tested experimentally for the first time by investigating wave localization for elastic waves in structured thin plates [2]. We show that regions of wave confinement can be predicted from the knowledge of the static deformation of the plate. These results reveal the predictive power of the "localization landscape" function, especially when a structural or microscopic description of the system is not accessible.

[1] M. Filoche, and S. Mayboroda, Proceedings of the National Academy of Sciences 109, 14761-14766 (2012).

[2] G. Lefebvre, A. Gondel, M. Dubois, M. Atlan, F. Feppon, A. Labbé, C. Gillot, A. Garelli, M. Ernoult, S. Mayboroda, M. Filoche, and P. Sebbah, Phys. Rev. Lett. 117, 074301 (2016).

Dynamics in Networks of Cultured Neurons Prof. Elisha Moses, Dept. of Physics of Complex Systems, Weizmann Institute of Science
Prof. Elisha Moses, Dept. of Physics of Complex Systems, Weizmann Institute of Science

Cultured networks of neurons from hippocampus constitute a fascinating reductionist model for biological computation. While individual neurons retain the physiological characteristics as in the intact brain, the structure and connectivity in the network are considerably simpler to measure and analyze, and therefore to engineer and design. We show that disconnected single neurons oscillate independently of each other, and that when the network is connected they synchronize into periodic network bursts in which all neurons fire together. This behavior is attributed to Kuramoto-Strogatz like behavior for the synchronization of pulse-coupled oscillators. We investigate how initiation of this burst is brought about, and find that the recruitment of a minimal cohort of firing units plays a crucial role in the process. Activation of the whole network is well described by a theoretical model of percolation invoking the need for ‘quorum’ decision making.

Highly confined electronic conduction– A peek into the field of oxide heterostructures Nini Pryds, Department for Energy Conversion and Storage, Technical University of Denmark
Nini Pryds, Department for Energy Conversion and Storage, Technical University of Denmark


The conductance confined at the interface of complex oxide heterostructures provides new opportunities to explore nanoelectronic as well as nanoionic devices. In this talk I will present our recent results on electronic conductivity at different heterostructures systems. I will discuss and show what is happening when two oxides intimately contact each other, charge redistribution or mass transfer of ions may occur. Our recent results of high mobile samples realized by, interface confined redox reactions [1], strain induced polarization [2] and modulation doping [3] at complex oxide interfaces. Based on the enhanced mobility we have recently studied the Quantum Hall Effect (QHE) which reveal the strength of enhancing the mobility [4]. This collection of samples offers unique opportunities for a wide range of rich world of mesoscopic physics.


[1]  Y. Z. Chen & N. Pryds et al. “A high-mobility two-dimensional electron gas at the spinel/perovskite interface of γ-Al2O3/SrTiO3”. Nature Commun. 4, 1371 (2013)

 [2] Y. Z. Chen & N. Pryds et al. “Creation of High Mobility Two-Dimensional Electron Gases via Strain Induced Polarization at an Otherwise Nonpolar Complex Oxide Interface” Nano Letters. 3774-3778 (2015) 10.1021/nl504622w

 [3] Y. Z. Chen & N. Pryds et al. “Extreme mobility enhancement of oxide 2DEGs via charge transfer induced modulation doping.” Nature Materials, 14 (8), 801-806 (2015)

 [4] F. Trier &N. Pryds et al., “Quantization of Hall Resistance at the Metallic Interface between an Oxide Insulator and SrTiO3” Physical Review Letters, 117, 096804 (2016)

Floquet's Theorem, Topology, and Transport in Two Dimensions Herb Fertig, Dept. of Physics, Indiana University at Bloomington
Herb Fertig, Dept. of Physics, Indiana University at Bloomington

In some two-dimensional systems, electrons have topological properties
which endow them with surprising transport properties.  While nature
provides us with a few such materials, their topology is limited by the materials
which can actually be synthesized.  In this talk I will review recent work
in which such topology is induced by time-dependent potentials, allowing
in principle a broad set of possibilities for topological bands to be
created. These "Floquet Topological Insulators" support
surprising fundamental behaviors,  including a quantized Hall effect with
no magnetic field, and in some cases transport enhancement by
disorder. In this talk I will discuss how these possibilities play out for electrons in graphene,
showing how a time-dependent electric field yields a rich set of topological phases,
and how they support phenomena which cannot be realized in a static setting.

Yitzhak Rabin

We use computer simulations to study multi-component systems in which all the particles are different (APD). The particles are assumed to interact via Lennard-Jones potentials with identical size parameters, but with pair interaction parameters generated at random from some distribution. We analyze these systems at temperatures above and below the freezing transition and find that APD fluids relax into a non-random state characterized by clustering of particles according to the values of their pair interaction parameters (Neighborhood Identity Ordering - NIO). We study the NIO using the random bond lattice model and show that the transition from frozen to annealed disorder depends not only on temperature but also on system size. We use a variant of the APD model to study the competition between specific and non-specific interactions and show that contrary to intuitive expectations the latter can assist in the formation of specific complexes. The relevance of our results to biological systems is discussed.

Probing Quantum Matter in Artificial Crystals of Light Prof. Immanuel Bloch, Max-Plank-Institute for Quantum Optics, Garching, Germany
Prof. Immanuel Bloch, Max-Plank-Institute for Quantum Optics, Garching, Germany

More than 30 years ago, Richard Feynman outlined the visionary concept of a quantum simulator for carrying out complex physics calculations. Today, his dream has become a reality in laboratories around the world. In my talk I will focus on the remarkable opportunities offered by ultracold quantum gases trapped in optical lattices to address fundamental physics questions ranging from condensed matter physics over statistical physics to high energy physics with table-top experiment.

For example, I will show how it has now become possible to image and control quantum matter with single atom sensitivity and single site resolution, thereby allowing one to directly image individual quantum fluctuations as well as spin and charge correlations of a many-body system. Such ultrahigh resolution and sensitivity have also enabled us to detect ‘Higgs’ type excitations occurring at 24 orders of magnitude lower energy scales than in high energy physics experiments and to observe antiferromagnetic order in the Fermi Hubbard model. Finally, I will show how the unique control over ultracold quantum gases has enabled the realization of artificial magnetic fields of extreme field strengths that will allow to probe quantum matter in completely new parameter regimes.

Probing the Atomic Higgs Force Gilad Perez, Dept. of Particle Physics and Astrophysics, Weizmann Institute of Science
Gilad Perez, Dept. of Particle Physics and Astrophysics, Weizmann Institute of Science
After the discovery of the Higgs particle at the Large Hadron Collider, the Higgs mechanism is expected to account for all observed masses of the the fundamental, point like, particles. We briefly argue that, while this is true for the mediators of the weak force (the W and Z gauge bosons), we are still in the dark regarding the origin of the charged fermions masses. In particular, the nature of the masses of the building blocks of matter, the electron and up and down quarks is an open question, both theoretically and experimentally. 
It motivates us to propose a non-collider approach to probe Higgs boson couplings to these matter constituents via precision measurement of isotope shifts in atomic clock transitions. We present an experimental method which, given state-of-the-art accuracy in frequency comparison, competes with and potentially surpasses the Large Hadron Collider in bounding the Higgs-to-light-fermion couplings. Better knowledge of the latter is an important test of the Standard Model which could lead, besides the establishment of new physics above the weak scale, to an alternative understanding of the flavor puzzle (namely the fact that the fermions masses span five orders of magnitude in scale).
If time permits we will then discuss how to translate the above (potential) fantastic sensitivity to constrain the presence of heavy new degrees of freedom that are well beyond the reach of near future accelerators. 
Prof. Ido Kanter, Physics Department, Bar Ilan University

Realizations of low firing rates in neural networks usually require globally balanced distributions among excitatory and inhibitory synapses, while feasibility of temporal coding is limited by neuronal millisecond precision. We show, experimentally and theoretically, that low firing rates as well as cortical oscillations stem from neuronal plasticity in the form of neuronal stochastic neuronal response failures emerge, as exemplified both in in-vitro and in-vivo experiments. Those failures appear in such a way that the neuron functions similar to a low pass filter, saturating its average inter-spike-interval. This intrinsic neuronal plasticity leads to cooperation on a network level, which suppresses the firing rates towards the lowest neuronal critical frequency simultaneously with the stabilization of the neuronal response timings to ms precision. In addition, this neuronal plasticity counterintuitively leads to the simultaneous emergence of macroscopic d and g oscillations in excitatory networks. A quantitative interplay between the statistical network properties and the emerging oscillations is supported by simulations of large networks that are based on single-neuron in-vitro experiments and a Langevin equation which describes the network dynamics. It is also supported by an experimental scheme where long-term stimulation and recording of a single neuron is used to mimic simultaneous activity measurements from thousands of neurons in a recurrent network.

A computational lens on quantum physics Dorit Aharonov, Dept. of Computer Science, Hebrew University
Dorit Aharonov, Dept. of Computer Science, Hebrew University

The new area of  quantum Hamiltonian complexity, which had emerged from quantum computation over the past decade, studies some of the most fundamental questions in quantum physics from a computational viewpoint.
This approach turns out to offer deep insights for physics (as well as computer science) which are now beginning to be revealed. I will attempt to describe some achievements from this fast growing vibrant area;
Connections to area laws, simulating condensed matter physics, stability of entanglement, precision measurements and even black holes will be mentioned, with emphasis on the many exciting open questions in this field.

Manipulating Electrons with Intense Lasers Prof. Victor Malka, Ecole Polytechnique, Université Paris-Saclay, France and Weizmann Institute of Science
Prof. Victor Malka, Ecole Polytechnique, Université Paris-Saclay, France and Weizmann Institute of Science

Laser Plasma Accelerators (LPA) rely on the control of the electrons motion with intense laser pulses [1]. The manipulation of electrons with intense laser pulses allows a fine mapping of the longitudinal and radial components of giant electric fields that can be optimized for accelerating charged particle or for producing X rays. To illustrate the beauty of laser plasma accelerators I will show, how by changing the density profile of the gas target, one can improve the quality of the electron beam, its stability [2] and its energy gain [3], or by playing with the radial field one can reduce its divergence [4]. I’ll then show how by controlling the quiver motion of relativistic electrons intense and bright X-rays beam are produced in a compact and elegant way [5,6]. Finally I’ll give some examples of applications [7].

References :

[1] V. Malka, Phys. of Plasmas 19, 055501 (2012).

[2] E. Guillaume et al., Phys. Rev. Lett. 115, 155002 (2015).

[3] C. Thaury Scientific Report, 10.1038, srep16310, Nov. 9 (2015).

[4] C. Thaury et al., Nature Comm. 6, 6860 (2015).

[5] K. Ta Phuoc et al., Nature Photonics 6, 308-311 (2012).

[6] S. Corde et al., Review of Modern Phys. 85 (2013).

[7] I. Andriyash et al., Nature Comm. 5, 4736 (2014).


Order and Chaos in the Quantum World Alessandro Silva, SISSA, Trieste
Alessandro Silva, SISSA, Trieste

This Public Lecture is the opening talk of the Italy-Israel meeting on "Non-Equilibrium Physics: Theory and Experiments of Quantum Many Body Dynamics".

Fredholm Index interpretation of the integers in the Quantum Hall Effect Yosi Avron, Faculty of Physics, the Technion
Yosi Avron, Faculty of Physics, the Technion

The integer conductances in the quantum Hall effect are related to topological invariants known as Chern numbers. A different interpretation relates them to invariants known as Fredholm indices. I will give a tutorial and an introduction to the Fredholm Index interpretation of the integers in the Quantum Hall Effect.

TBA Yosi Avron, Faculty of Physics, Technion
Yosi Avron, Faculty of Physics, Technion


Correlation Effects in Quantum Point Contacts Yigal Meir, Dept. of Physics, Ben-Gurion University
Yigal Meir, Dept. of Physics, Ben-Gurion University

Quantum point contacts (QPCs), are the basic building blocks of any mesoscopic structure, and display quantized conductance, reflecting the quantization of the number of transparent channels. An additional feature, coined the "0.7 anomaly", has been observed in almost all QPCs, and has been a subject of intensive debate in the last couple of decades. In the past we have attributed this feature to the emergence of a quasi-localized state at the QPC, which explains all the phenomenology of the effect. In this talk I will review the physics of the effect, and describe two new experiments, and relevant theories, one which measured the thermoelectric power through the QPC, and another which measured the conductance through length-tunable QPC. The experimental findings support the picture of the localized state(s). Interestingly, with increasing QPC length, it was found that both the 0.7 anomaly and the zero bias peak in the differential conductance oscillate and periodically split with channel length, supporting the idea that the number of the localized states increases with length, leading to an alternating Kondo effect.

Clusters as Surfaces Gereon Niedner-Schatteburg/Kaiserslautern University - Germany
Gereon Niedner-Schatteburg/Kaiserslautern University - Germany

Clusters – in particular those of transition metals – may act like surfaces of limited size, this analogy being recognized long time ago [1,2]. We have studied the C-H bond activation of various organic molecules by naked transition metal clusters before [3], and it became mandatory to switch to simpler systems. By virtue of our tandem cryo ion trap instrument we study the adsorption kinetics of clusters under single collision conditions as well as the Infrared Multiple Photon Dissociation (IR-MPD) by application of optical parametric oscillator/amplifier (OPO/OPA) photon sources, one and two colour investigations of metal organic complexes by such technique being published [4].

Our ongoing studies of N2 and H2 cryo adsorption on Fe, Co, and Ni clusters and alike [5] revealed clearly discernible mono layer like adsorbate shells. Beyond such mere kinetics – though interesting in themselves – we recorded IR-MPD spectra of dinitrogen stretching vibrations within such [Mn(N2)m]+ cluster surface – adsorbate layer complexes by variation of their stoichiometry, n and of m alike, and in conjunction with electronic structure modelling (by DFT), and with synchrotron X-ray based studies of  spin and orbital contributions to the total magnetic moments of the isolated clusters [6].

This invited presentation shall elucidate the current state of cluster adsorbate studies under cryo conditions and in isolation. It aims to put into perspective the findings from adsorption kinetics, IR spectroscopy, DFT modelling and magnetic spectroscopy. It concludes with an outlook onto the road ahead.

This research originates from a long standing support by the DFG through the transregional collaborative research center SFB/TRR 88


[1] E. L. Muetterties, T. N. Rhodin, E. Band, C. F. Brucker, W. R. Pretzer, Chem. Rev., 1979, 79, 91-137. [2] G. Ertl, Angew. Chem. Int. Ed., 2008, 47, 3524 – 3535. [3] B. Pfeffer, S. Jaberg, and G. Niedner-Schatteburg, J. Chem. Phys. 2009, 131, 194305; L. Barzen, M. Tombers, C. Merkert, J. Hewer, and GNS, Int. J. Mass Spectrom. 2012, 330–332, 271–276; M. Tombers, L. Barzen, and GNS, J. Phys. Chem. A 2013, 117, 1197-1203. [4] Y. Nosenko, F. Menges, C. Riehn, GNS, Phys. Chem. Chem. Phys. 2013, 15, 8171; J. Lang, M. Gaffga, F. Menges, and GNS, Phys. Chem.Chem. Phys. 2014, 16, 17417 – 17421. [5] S. Dillinger, J. Mohrbach, J. Hewer, M. Gaffga, and GNS, Phys. Chem. Chem. Phys. 2015, 17, 10358. [6] S. Peredkov, M. Neeb, W. Eberhardt, J. Meyer, M. Tombers, H. Kampschulte, GNS, Phys. Rev. Lett. 2011,         107, 233401; J. Meyer, M. Tombers, C. van Wüllen, GNS, S. Peredkov, W. Eberhardt, M. Neeb, S. Palutke, M. Martins, and W. Wurth, J. Chem. Phys. 2015, 143, 104302.

Molecular dynamics studies of emergent phenomena (with GPU teraflops) Prof. D. Rapaport, Physics Department, BIU
Prof. D. Rapaport, Physics Department, BIU

Emergent phenomena are especially fascinating because they are not obvious consequences of the design of the systems in which they appear, a characteristic equally relevant when attempting to simulate them. Several systems that exhibit surprisingly rich emergent behavior will be described, each studied by MD (molecular dynamics) simulation. (a) In the case of fluids studied at the atomistic level, not only can complex hydrodynamic phenomena in convecting and rotating fluids - the Rayleigh-Benard and Taylor-Couette instabilities - be reproduced within the limited length and time scales accessible to MD, but there is even quantitative agreement. (b) Modeling self-assembly processes associated with virus capsid growth reveals the ability to achieve complete, error-free shells, where paradoxically, high yields are due to reversible bond formation. (c) Studies of granular mixtures show behavior that, in the case of a rotating drum, reproduces known but counterintuitive axial and radial segregation, and in the case of a vertically vibrated layer, predicts a novel form of horizontal segregation. These simulations tend to be comparatively large and lengthy, and in some cases multiple runs are needed because the outcomes are unpredictable, so the use of GPU-based parallel computing is beneficial; the methodology involved will be outlined. While MD is subject to limitations, both conceptual and computational, the results offer exciting indications of what can be accomplished.

CSI Rivers: Fluvial fingerprints of tectonic activity Liran Goren, Dept. of Geological and Environmental Sciences, Ben-Gurion University
Liran Goren, Dept. of Geological and Environmental Sciences, Ben-Gurion University

Bedrock rivers carve the surficial pattern of valleys and ridges that characterizes fluvial terrains in high mountains.  When tectonic forces act on the upper crust of the Earth and cause it to deform, the surface of the Earth, which is the upper boundary of the crust and the river valleys that are imprinted in the crust take part in the deformation. We have some understanding of how tectonically induced deformation reshapes the long profile of rivers and the map pattern of fluvial drainage networks, but can we solve the inverse problem of inferring rates and modes of deformation from the shape of drainage networks? In this talk I will review two field cases: one from the Basin and Range province in the US where rivers are used to infer temporal variations of tectonic uplift rates, and the second from Mount Lebanon where a suite of rivers is used to infer rates and modes of horizontal deformation along the Dead Sea fault system.

Ronny Bartsch, Dept. of Physics, Bar-Ilan

We study sleep-stage transitions and dynamical aspects of sleep micro-architecture. 
We find that sleep-stage transitions exhibit a high degree of asymmetry, and that the entire class of sleep-stage transition pathways underlying the complexity of sleep dynamics throughout the night can be characterized by two independent asymmetric transition paths. These basic pathways remain stable under sleep disorders, even though the degree of asymmetry is significantly reduced. Our findings further demonstrate an intriguing temporal organization in sleep micro-architecture at short time scales that is typical for physical systems exhibiting self-organized criticality, and indicates non-equilibrium critical dynamics in brain activity during sleep.

Topological Phases in Atomic, Molecular, and Optical Systems Alexey Gorshkov, Joint Quantum Institute, NIST and University of Maryland
Alexey Gorshkov, Joint Quantum Institute, NIST and University of Maryland

We will first review schemes for taking advantage of the tremendous degree of control recently achieved in AMO (atomic, molecular, and optical) systems to realize topological phenomena. In particular, we will emphasize unique features of AMO systems such the abundance of bosonic platforms, accessibility of far-out-of-equilibrium dynamics, and natural occurrence of interactions decaying as tunable power laws. We will then focus on a few examples such as symmetry protected topological phases with ion crystals, various fractional quantum Hall states with dipoles, and parafermionic zero modes with ultracold neutral bosons.

Between Localization and Ergodicity in Quantum Systems Boris Altshuler, Columbia University, New York
Boris Altshuler, Columbia University, New York

Strictly speaking the laws of the conventional Statistical Physics, in particular the Equipartition Postulate, apply only in the presence of a thermostat. For a long time this restriction did not look crucial for realistic systems. Recently there appeared two classes of quantum many-body systems with the coupling to the outside world that is (or is hoped to be) negligible: (1) cold quantum gases and (2) systems of qubits, which enjoy a continuous progress in their disentanglement from the environment. To describe such systems properly one should revisit the very foundations of the Statistical Mechanics. The first step in this direction was the development of the concept of Many-Body Localization (MBL) [1]:  the states of a many-body system can be localized in the Hilbert space resembling the celebrated Anderson Localization of single particle states in a random potential. Moreover, one-particle localization of the eigenfunctions of the Anderson tight-binding model (on-site disorder) on regular random graphs (RRG) strongly resembles a generic MBL.

 MBL implies that the state of the system decoupled from the thermostat depends on the initial conditions: the time averaging does not result in equipartition distribution, the entropy never reaches its thermodynamic value i.e. the ergodicity is violated. Variations of e.g. temperature can delocalize many body states. However, the recovery of the equipartition is not likely to follow the delocalization immediately: numerical analysis of the RRG problem suggests that the extended states are multi-fractal at any finite disorder [2]. Moreover, regular (no disorder!) Josephson junction arrays (JJA) under the conditions that are feasible to implement and control experimentally demonstrate both MBL and non-ergodic behavior [3].

1.  D. Basko, I. Aleiner, and B. Altshuler, Ann. Phys. 321, 1126 (2006).

2. A. De Luca, B.L. Altshuler, V.E. Kravtsov, & A. Scardicchio, PRL 113, 046806, (2014)

3. M. Pino, B.L. Altshuler and L.B. Ioffe, arXiv:1501.03853, PNAS to be published.

Charge Order and Superconductivity in Low-Dimensional Organic Conductors Martin Dressel, Physikalisches Institut, Universität Stuttgart, Germany
Martin Dressel, Physikalisches Institut, Universität Stuttgart, Germany

Molecular solids provide the opportunity to create materials of desired properties and function­nalities by tailoring the constituents and tuning their interactions. The interplay of electronic, magnetic and lattice degrees of freedom allows us to tackle fundamental questions of competing interactions. A slight variation of the constituents and proper arrangement, for instance, causes localization of the conduction electrons, drives a Mott insulator superconducting or establishes magnetic order. The exemplary collaboration of chemists, materials scientists, experimental and theoretical physicists has advanced our understanding of organic con­ductors enormously in the last years, albeit the potential of molecular solids is far from being fully explored.

Organic charge-transfer salts are a well-established class of strongly-correlated electron sys­tems; many of them are subject to ordering phenomena in the spin or charge sector. Some of the two-dimensional quarter- filled BEDT-TTF salts are superconductors, while some of them remain metallic down to low temperatures; others undergo a sharp metal to insulator transition. Why do these materials behave electronically so differently although they are similar in structure? Optical spectro­scopy complemented by magnetic investi­gations reveals that these compounds are subject to charge order to a different degree. The interplay of charge order and superconductivity suggest superconductivity mediated by charge fluctuations.

Towards coupling a superconducting circuit with a single spin Dr. Michael Stern, Department of Physics, Bar Ilan University
Dr. Michael Stern, Department of Physics, Bar Ilan University

Superconducting qubits are often considered as a leading potential candidate for the physical realization of a quantum computer. These qubits can be easily fabricated, manipulated and coupled together using simple linear electrical elements like capacitors, inductors and transmission lines. However, they suffer from rather poor coherence times due to their macroscopic size.

A promising research direction is to combine these qubits with spins in semiconductors and construct a hybrid quantum system. Indeed, spins may have extremely long coherence times and could therefore be a perfect system to reliably store the quantum information while superconducting qubits with their strong coupling with external fields are perfect systems to easily process fast quantum gates.

Efficient transfer of quantum information between these systems requires reaching the so-called “strong coupling regime” where the coupling between the different systems is much larger than their decoherence rates.  In this talk, I will present our progress and current experimental efforts in the quest for reaching the strong coupling regime between a superconducting circuit and a single spin [1-3]. 

1] M. Stern et al., Phys. Rev. Lett. 113, 123601 (2014).

[2] T. Douce et al., Phys. Rev. A, 92, 052335 (2015).

[3] A. Bienfait et al., Nature Nanotechnology, 282,1038 (2015).


Evolutionary tradeoffs and the geometry of biological shape space Uri Alon, Dept. of Molecular Cell Biology, Weizmann Institute
Uri Alon, Dept. of Molecular Cell Biology, Weizmann Institute

Organisms, tissues and molecules often need to perform multiple tasks. But usually no phenotype can be optimal at all tasks at once. This leads to a fundamental tradeoff. We study this using the concept of Pareto optimality from engineering and economics. Tradeoffs lead to an unexpected simplicity in the range of optimal phenotypes- they fall on low dimensional shapes in trait space such as lines, triangles and tetrahedrons. At the vertices of these polygons are phenotypes that specialize at a single task. One does not need to know the tasks in advance; tasks  can be inferred from the data. We demonstrate this using animal and fossil morphology, bacterial and stem-cell gene expression and other biological systems.

1/f noise and low-frequency cutoff paradox Prof. Eli Barkai, Department of Physics, Bar Ilan University
Prof. Eli Barkai, Department of Physics, Bar Ilan University

Starting with the work of Bernamont (1937) on resistance uctuations, noisy signals of a vast number of natural processes exhibit 1/f power-spectrum. This power spectrum is non-integrable implying that the total energy in the system is infnite. As pointed out by Mandelbrot (1950's) this infrared catastrophe suggests that one should abandon the stationary mind set and hence go beyond the widely applicable Wiener-Khinchin formula for the power spectrum. Recent theoretical and experimental advances renewed the discussion on this old paradox, for example in the context of blinking quantum dots [1,2]. In this talk aging, intermittency, ergodicity breaking, and critical exponents of the sample power spectrum are discussed within a theoretical framework which hopefully provides new insight on the 1/f enigma [3].


[1] M. Niemann, H. Kantz, E. Barkai, Fluctuations of 1/f noise and the low frequency cutoff paradox, Phys. Rev. Lett. 110, 140603 (2013).
[2] S. Sadegh, E. Barkai, and D. Krapf, 1/f noise for intermittent quantum dots exhibits non-stationarity and critical exponents, New. J. of Physics 16 (2014)
[3] N. Leibovich and E. Barkai, Aging Wiener-Khinchin Theorem, Phys. Rev. Lett. 115, 080602 (2015).

Graphene and the magic of physics in two dimensions Eva Andrei, Dept. of Physics and Astronomy, Rutgers University,
Eva Andrei, Dept. of Physics and Astronomy, Rutgers University,

Since its first scotch-tape extraction from graphite in 2004, Graphene – a one atom-thick crystal of carbon - has metamorphosed from the poor relative of diamond into a “wonder material”. By now it has amassed an impressive string of superlatives (lightest, thinnest, strongest material, best electrical and thermal conductor) and a host of close 2D relatives extracted from other layered materials. Due to their remarkable properties 2D materials are rapidly moving from research laboratories into industrial, medical and electronics applications. For physicists much of the continuing excitement about graphene stems from its exotic charge carriers - Dirac fermions - which resemble two dimensional massless neutrinos.  I will review the story and physics of graphene  with emphasis on its fascinating electronic properties as viewed through scanning tunneling microscopy and Landau level spectroscopy experiments performed in my group.

Moving from Physics to Biology: the Upsides, Downsides & Unexpected Sides Prof. Eytan Domany, Dept of Physics of Complex Systems, Weizmann Institute of Science
Prof. Eytan Domany, Dept of Physics of Complex Systems, Weizmann Institute of Science

My move from Theoretical Physics to Biology has exposed me to quite a few significant differences between the disciplines. I try to describe some of these and to point out the aspects of this momentous move that were gratifying and those which I found frustrating. I assume some basic knowledge of Biology, but will try to explain things in a way that will be understandable to a Physics audience. While the talk may be perceived as provocative by some, I do promise that it will not be boring!

Quantum Walks in Photonic Lattices Prof. Yaron Silberberg, Department of Physics of Complex Systems, Weizmann Institute of Science
Prof. Yaron Silberberg, Department of Physics of Complex Systems, Weizmann Institute of Science

Random quantum walk is the process describing the motion of a quantum particle that hops randomly, yet coherently, from site to site on a lattice. The coherent motion induces a big difference between quantum walks, for example the motion of an electron in a lattices, and classical random walks, that are responsible for processes such as molecular diffusion. We study quantum walks of photons in 'photonic lattices' that are made of arrays of optical waveguides that are close enough to allow photons to hop between them. Such lattices have been used for more than a decade to study some of the most basic phenomena of wave propagation in periodic and quasi-periodic structures, from Bloch Oscillations to Anderson Localization.  While most work with photonic  lattices have studied wave propagation using coherent laser light, we have shown that they could also serve as an excellent platform for the study of quantum dynamics, and in particular of quantum walks. We have extended this concept to more complex random walks of several particles, and have shown that such walks by indistinguishable particles lead to new and surprising effects on the quantum correlations of the co-propagating walkers in periodic lattices. Even more surprises are found when the quantum walkers move in a disordered lattice where the particles are also constrained via Anderson localization, and I will present recent experiments on such systems.

Solving the two body problem in Einstein's gravity Barak Kol, Racah Institute of Physics, Hebrew University
Barak Kol, Racah Institute of Physics, Hebrew University

The two body problem in Einstein's gravity has both intrinsic theoretical interest, as well as importance for the ongoing observational search for gravitational waves. This talk will explain how field theory ideas and techniques were used to perturbatively solve the two-body problem in the slow velocity post-Newtonian limit. Central notions include the two-body effective action, field elimination through Feynman diagrams, a non-relativistic decomposition of Einstein's field, and finally divergences, their regularization and renormalization. This approach is known as the Effective Field Theory approach to General Relativity.

Robust Electron Pairing in the Integer Quantum Hall Effect Regime Moty Heiblum, Dept. of Condensed Matter Physics, Weizmann Institute
Moty Heiblum, Dept. of Condensed Matter Physics, Weizmann Institute

Electron pairing is a rare phenomenon appearing only in a few unique physical systems; e.g., superconductors and Kondo-correlated quantum dots. Here, we report on an unexpected, but robust, electron ‘pairing’ in the integer quantum Hall effect (IQHE) regime. The pairing takes place within an interfering edge channel circulating in an electronic Fabry-Perot interferometer at a wide range of bulk filling factors, 2<νB<5. The main observations are: (a) High visibility Aharonov-Bohm conductance oscillations with magnetic flux periodicity Delta(φ)=ϕ0/2=h/2e (instead of the ubiquitous h/e), with e the electron charge and h the Planck constant; (b) An interfering quasiparticle charge e*~2e - revealed by quantum shot noise measurements; and (c) Full dephasing of the h/2e periodicity by induced dephasing of the adjacent edge channel (while keeping the interfering edge channel intact) – a clear realization of inter-channel entanglement. While this pairing phenomenon clearly results from inter-channel interaction, the exact mechanism that leads to e-e attraction within a single edge channel is not clear.

The genome in the nucleus: 
snaky, dynamic and yet organized Prof. Yuval Garini, Physics Department & Institute of Nanotechnology, Bar Ilan University
Prof. Yuval Garini, Physics Department & Institute of Nanotechnology, Bar Ilan University

The DNA in a human cell is ~3 meters long. It is dynamic and although there are no definite structures that maintain the order in the nucleus, the genome is well organized. What are the mechanisms that organizes the DNA in the nucleus?

Dynamic methods in live cells are ideal for studying the genome organization, as it is mainly made of soft-matter that have no definite structure.

We used single particle tracking (SPT) and continuous photobleacing (CP) that are adequate for live-cell imaging and the data is analyzed according to diffusion analysis methods. In normal cells, all the sites in the genome exhibit anomalous diffusion (viscoelastic) with a power law of ~0.3-0.5 and the diffusion was found to belong to the family of fractional Brownian motion anomalous diffusion.

We rationalized that the source of the viscoelasticity is a protein that can temporarily bind chromatin. We identified one source protein (lamin A) that dramatically affects the diffusion pattern and leads to a phase transition from viscoelastic to viscous diffusion when its expression is inhibited. We suggest a rather simple mechanism that explains the organization maintenance of the chromosomal territories. It is based on the properties of the DNA itself organized by cross-links of lamin A and mediated by other proteins.

High Energy physics meets solid state research Amit Keren, Faculty of Physics, Technion
Amit Keren, Faculty of Physics, Technion

In this talk I will present progress in the use of high energy particles, produced at accelerators or reactors, to address problems in solid state physics. In particular I will review advances in neutron scattering, muon spin resonance, and Resonance Elastic and Inelastic X-ray spectroscopy. I will provide examples from the field of high temperature superconductivity.

Edward Bormashenko

Self-propulsion of liquid marbles filled with aqueous alcohol solutions and placed on a water surface is reported. The characteristic of velocity of the marbles is ca. 0.1 m/s. The phenomenon of self-propulsion is related to the Marangoni solutocapillary flow caused by the condensation of alcohol, evaporated from the liquid marble, on a water surface. The Marangoni flow in turn enhances the evaporation of alcohol from marbles. Addition of alcohol to the water supporting the marbles suppresses the self-propulsion. The propulsion of liquid marbles is mainly stopped by water drag. The velocity of the center of mass of marbles grows with the increase of the concentration of alcohol in a marble. The velocity of marbles’ self-propulsion is independent on their volume. Impact of external fields on the self-propulsion is discussed.

Host: Eli Sloutskin, Physics Department (phone. 03 - 738 4506; cell. 054 - 393 8246)
Those of you who may be interested in talking with Prof. Bormashenko should mail me (, listing their preferred time.



Orientation-dependent handedness and chiral design Prof. Efi Efrati, Dept. of Physics, Weizmann Institute
Prof. Efi Efrati, Dept. of Physics, Weizmann Institute

Handed phenomena are of central importance in fields ranging from biological self-assembly to the design of optical meta-materials. The definition of chirality (Greek for handedness), as given by Kelvin, associates it with the lack of mirror symmetry: the inability to superpose an object on its mirror image. While this definition has guided the classification of chiral objects for over a century, the quantification of handed phenomena based on this definition has proven elusive, if not impossible as manifest in the paradox of chiral connectedness. In this talk I will put forward a quantification schemein which the handedness of an object depends on the direction in which it is viewed and thus best quantified by a pseudo-tensor. While consistent with familiar chiral notions, such as the right hand rule, this framework allows objects to be simultaneously right and left handed. The trace of the suggested handedness tensors recover Kelvin's definition, yet their full structure is richer, and proven to be in quantitative agreement with the direction-dependent handed behavior of phenomena ranging from fluid flow to optical activity. I will review specific examples of handedness tensors, and discuss how the tensorial approach resolves the existing paradoxes and naturally enables the design of handed meta materials from symmetry principles.

Superconducting Qubits, Resonators and Beyond Nadav Katz, HUJI
Nadav Katz, HUJI

Superconducting devices, containing Josephson junctions and resonant structures, are at the forefront of quantum information science today. These devices, built with various  nanofabrication  techniques  and  resulting  in  tunable  and  highly  nonlinear  resonances, uncover  also exciting  physics  of  the  superconducting  state  and surrounding  dielectric  and  magnetic  environment.  I  will  review  some  of  the recent progress in  the  field  and  present  some  of  our  results on both quantum optical control and subsequent metrology of two-level  defect  states and magnetic flux noise in the environment. 

From Topology to Morphology: Defects, Shape Evolution, and Auto-origami in Soft Matter Prof. Robin Selinger, Kent State University
Prof. Robin Selinger, Kent State University

We explore novel mechanisms of pattern formation in soft matter, examining why a lipid membrane crumples during a phase transition and how stimuli-responsive liquid crystal polymer films can be patterned to induce programmed shape transformations . In both of these materials, whose constituent molecules align to form orientationally ordered phases, topological defects play a key role: they drive changes in morphology by inducing curvature. In lipid membranes cooled through a phase transition into the tilted “gel” phase, we theorize that defects nucleate spontaneously and then coarsen via kinetic competition between defect pair-annihilation and membrane shape evolution. We explore this process via simulation using a coarse-grained model and also study membranes with nematic order. Next we examine the role of defects in stimuli-responsive liquid crystal polymers, which flex when exposed to light or a change of temperature. If a precise pattern of defects is induced in the sample when it is cross-linked, a process known as “blueprinting,” then under stimulus an initially flat film will twist, curl, or fold into a complex shape, a form of programmed auto-origami. We use 3-d nonlinear finite element simulation studies to explore the mechanism by which the complete trajectory of motion is encoded in the sample’s nematic director field, and compare with relevant experiments. 

Prof. Issai Shlimal, BIU

The phenomenal mechanical, thermal, electrical and optical properties discovered in recent years from the first true two-dimensional material - monolayer graphene have attracted the tremendous enthusiasm because of possible graphene-based device application. In this sense, the influence of disorder is interesting due to possibility of obtaining a high-resistance state, which is important for application in electronics. In the experiment, disorder in graphene is introduced in various ways: by oxidation, hydrogenation, chemical doping, as well as irradiation by different ions with different energies. The advantage of the latter method consists in an accuracy and reproducibility of the process and ability to anneal the radiation damage.

In this talk, I will make an introduction into the subject, followed by presentation of the results of investigation of the properties of monolayer graphene samples gradually disordered by ion bombardment. To probe the evolution of disorder, the Raman spectroscopy (RS) and resistance measurements were used. The main new results of this work consist in (i) observation of the utmost degree of disorder, when graphene, due to high density of defects, is no longer continuous film but split into separate fragments; (ii) observation of the correlation between intensity of RS lines and sample resistance: transition from the low-defect to the high-defect density regime occurs at the resistance equal to reciprocal value of the minimal graphene conductivity. (iii) observation of gradual change in the mechanism of electron transport from metallic conductivity in the initial pristine films to the regime of weak localization-weak antilocalization in the weakly disordered samples and finally to the variable-range hopping conductivity of localized carriers in strongly disordered graphene.

The Higgs Boson-from Superconductors to Supercolliders and back Prof. Aviad Frydman, BIU
Prof. Aviad Frydman, BIU

The 2013 Nobel Prize in physics was awarded to Peter Higgs and Francois Englert "for the theoretical discovery of the mechanism that contributes to our understanding of the origin of mass of subatomic particles". This Nobel committee decision was based on the detection of the predicted "Higgs boson" in the CERN Large Hydron Collider within the framework of the largest experiment ever held by mankind. Obviously, this recent discovery regarding the "God Particle" generated much worldwide interest. But what is less known is that the inspiration for its prediction came from theoretical works in the field of Superconductivity. 

Ironically, while the ideas regarding this ‘missing link’ in the Standard Model of elementary particles were stimulated by superconductor theory, the Higgs mode was never clearly observed in superconductors. The main reason for this is the fact that the energy required to excite the Higgs boson, the Higgs mass, is large enough to break cooper-pairs and hence suppress superconductivity.  Nevertheless, recent theories show that if the Higgs mass could be softened below the superconducting gap it should be visible in two dimensions. Such conditions can be met by tuning a superconducting film towards a superconductor-insulator quantum phase transition. Indeed, in our experimental study on thin superconducting films for which the superconductor to insulator transition is tuned by disorder, an excess optical spectral weight below the superconducting gap energy was observed and identified as an explicit observation of the Higgs mode in a superconductor. 

This experiment closes a historical circle by connecting the Higgs Boson to its theoretical "ancestor" and serves as a beautiful example that the same fundamental physics can govern in two disparate systems (elementary particles and conventional superconductors) for which the energy scales differ by 15 orders of magnitude.


Prof. Dan Shahar

We show that, at low temperatures (T<0.2 K), Copper-pairs undergoing localization transition become decoupled from the host-material phonons. This allows us to experimentally study an interacting, many-body, quantum system far from equilibrium. Our system exhibits complex dynamics alongside a new second-order phase transition.

Beena Kalisky, BIU

Complex oxide materials have a broad range of functionality such as ferromagnetism,piezoelectricity, and superconductivity. When combinations of complex oxides are grown as heterostructures, changes in the local electronic-structure at the interface can create new electronic phases that cannot exist in either parent material. One example is the interface formed by growing LAO on STO. Though both materials are non magnetic insulators, the interface between them shows conductivity, superconductivity and even magnetism. 

In the LAO/STO system we found nanoscale patches of magnetism coexisting with superconductivity. I will describe our efforts to understand this magnetism, by mapping the landscape of ferromagnetism, superconductivity and conductivity with scanning SUQID microscopy. I will focus on viewing the local distribution of current flow at the interface, where we found that the current flow is enhanced on conductive channels that are related to STO tetragonal domain structure. The interplay between substrate domains and the interface provides an additional mechanism for understanding and controlling the behaviors of heterostructures.

Quantum phenomena in a chirped unharmonic oscillator Lazar Friedland, Hebrew University of Jerusalem
Lazar Friedland, Hebrew University of Jerusalem

Autoresonance is a fascinating phenomenon of nonlinear physics, where a perturbed nonlinear system is captured into resonance and stays phase-locked with perturbing oscillations (or waves) continuously despite variation of system's parameters. The persistent phase-locking means excursion in system's solutions space and frequent emergence of nontrivial coherent structures. For nearly half a century (starting from Veksler and McMillan in 1945) studies of autoresonance were limited to relativistic particle accelerators and microwave sources, but many new applications of the autoresonance idea emerged since 1990 in atomic physics, nonlinear dynamics, nonlinear waves, plasmas, fluid dynamics, and, most recently, superconducting Josephson junctions. 

The salient feature of autoresonance is the existence of a sharp threshold on the amplitude of the chirped frequency driving perturbation for autoresonant transition. In this talk I will discuss the effects of thermal noise and quantum fluctuations on the threshold. I will also address the quantum counterpart of the of the classical autoresonance phenomenon, i.e. the quantum ladder climbing and the continuous transition between these two regimes.

Prof. Francoise Remacle

The recent developments in the generation of optical attopulses suggest that it will soon become experimentally feasible to induce and subsequently directly probe ultrafast charge transfer between the end moieties of the modular molecule. One ultrafast pulse creates a non-stationary state of the neutral or of the cation and a second one ionizes it. Such experiments would allow characterizing a purely electronic time scale, before the coupling to the nuclei takes place. This is a pre Born-Oppenheimer regime where the electronic states are not stationary.[1]

We will report on the simulation of realistic pump probe experiments that monitor the ultrafast electronic dynamics in LiH,[2,3] in the medium size bifunctional molecule PENNA (C10H15N)[4] (Fig.1), C60 and other medium size molecules using a coupled equation scheme that includes the ionization continua and field effects. We show that in a short IR pump- XUV attosecond pulse train (APT) scheme that the APT can be used to disentangle the coherent superposition of states built by the IR pump pulse, acting as frequency filter.[2] The density motion between the two ends of a molecular system is probed by the anisotropy ionization parameter computed as the normalized difference between the ionization yields at the two moieties.[4] Heatmaps of the ionization anisotropy parameter as a function of the delay time between the two pulses and the kinetic energy of the photoelectron exhibit oscillations that reflect the beating periods of the electron density. 


[1] F. Remacle and R. D. Levine Proc. Natl. Acad. Sci. USA 2006, 103, 6793-6798.

[2] B. Mignolet, R. D. Levine, F. Remacle Phys. Rev. A 2014, 88, 021403(R).

[3] B. Mignolet, R. D. Levine and F. Remacle, J. Phys. Chem A 2014, 118 ,6721-6729.

[4] B. Mignolet, R. D. Levine, F. Remacle J. Phys. B 2014, J. Phys. B: 47, 124011.

When superconductor turns superinsulator Prof. Tatyana I. Baturina
Prof. Tatyana I. Baturina

For nearly a half century the dominant orthodoxy has been that the only effect of Cooper pairing is a state with zero resistivity at finite temperatures, superconductivity.  In this talk I will show that Cooper pairing can generate a dual state with zero conductivity in a finite temperature range, superinsulation.  Superconductor-superinsulator duality rests on the symmetry of the Heisenberg uncertainty principle relating the amplitude and phase of the superconducting order parameter. It is realized in the critical region of the quantum superconductor-insulator transition (SIT) in two-dimensional systems via the duality between the vortex and charge of the Berezinskii–Kosterlitz–Thouless transition. I will discuss the origin of the long-range logarithmic two-dimensional Coulomb forces between the charges ensuring the vortex-charge duality in the critical vicinity of the SIT.

Prof. Baturina is from A. V. Rzhanov Institute of Semiconductor Physics SB RAS, 13 Lavrentjev Avenue, Novosibirsk, 630090 Russia


In-vivo dynamics of chromatin and DNA-binding proteins studied by light sheet fluctuation microscopy Prof. Jörg Langowski, Biophysics of Macromolecules, DKFZ Heidelberg, Germany
Prof. Jörg Langowski, Biophysics of Macromolecules, DKFZ Heidelberg, Germany

Proteins acting on DNA need to penetrate a dense network of chromatin and associated macromolecules in the cell nucleus to access their target sites. Intracellular mobility of proteins is characterized by diffusion coefficients of the order of 1-100 μm2/s, leading to millisecond time scales for movement on the submicrometer scale.
Typical microscopic methods used for characterizing intracellular protein mobility are, e.g., fluorescence photobleaching recovery (FRAP) and fluorescence correlation spectroscopy (FCS). Of these, FRAP can image protein mobility in entire two-dimensional sections of live cells, but is typically limited to the time resolution of confocal image series, some frames per second. FCS, on the other hand, has fast time resolution but so far has been limited to single-point measurements in the focus of a laser beam, or to techniques that utilize the inherent time structure of confocal scans. In my seminar I will show results from single plane illumination microscopy based fluorescence correlation spectroscopy (SPIM-FCS), a new method that combines the fast time resolution of FCS with the ac- quisition of mobility data in parallel on an entire two-dimensional cross-section. This provides diffusion coefficients, flow velocities, concentrations and interactions as imaging parameters.

- The SQCRAMscope: Probing exotic materials with quantum gases Benjamin Lev
Benjamin Lev
Microscopy techniques co-opted from nonlinear optics and high energy physics have complemented solid-state probes in elucidating exotic order manifest in condensed matter materials.  Up until now, however, no attempts have been made to use modern techniques of ultracold atomic physics to directly explore properties of strongly correlated or topologically protected materials.  Our talk will present the SQCRAMscope, a novel Scanning Quantum CRyogenic Atom Microscope technique for imaging magnetic and electric fields near cryogenically cooled materials.  With our SQCRAMscope, we aim to image inhomogeneous transport and domain percolation in technologically relevant materials whose order has evaded elucidation.
Barak Dayan, WIS

I will present the recent demonstration of deterministic photon-atom and photon-photon interactions using a single atom coupled to a chip-based micro-resonator. Based on passive, interference-based nonlinearity which leads to deterministic single-photon Raman passage (DSPR), this scheme swaps the quantum states of a single photon and a single quantum emitter (a 87Rb atom, in our case), with no need for any control fields.
Beyond the ability to route single photons by single photons, this scheme can also function as a quantum memory and a photonic universal quantum gate. It can therefore provide a building block for scalable quantum networks based on completely passive nodes interconnected and activated solely by single photons.


[1] D. Pinotsi & A. Imamoglu, Phys. Rev. Lett. 100, 093603 (2008)

[2] G. Lin, X. Zou, X. Lin, and G. Guo, Europhysics Letters 86, 30006 (2009)

[5] K. Koshino, S. Ishizaka & Y. Nakamura, Phys. Rev. A 82, 010301(R) (2010)

[4] S. Rosenblum, A.S. Parkins & B. Dayan, Phys. Rev. A 84, 033854 (2011)

[5] I. Shomroni, S. Rosenblum, Y. Lovsky, O. Bechler, G. Guendelman & B. Dayan, Science 345, 903 (2014)

[6] S. Rosenblum & B. Dayan, “Analysis of Photonic Quantum Nodes Based onDeterministic Single-Photon Raman Passage”, arXiv: quant-ph 1412.0604 (2014) )

Prof. Giacomo Ghiringhelli

The appearance of superconductivity (SC) in layered cuprates upon doping with holes or electrons is still the matter of intense debate almost 30 years after the discovery of the so-called high Tc superconductors (HTcS). Given the strong superexchange interaction that stabilizes a 2D square lattice antiferromagnetic (AF) order in the parent compounds, the actual evolution of the spin order and its possible coupling to charge instabilities have been questioned and extensively studied over the years. In fact magnetic and/or charge fluctuations might play a central role in the superconductive transition. Moreover their possible relation with the pseudogap and the Fermi surface shape and size is still questioned. Working at the ESRF and SLS [1], in the last 10 years we have developed high resolution resonant inelastic x-ray scattering (RIXS) and used it at the Cu L3 edge of HTcS. This technique is the only alternative to inelastic neutron scattering for the study of magnons and paramagnons in those materials [2,3]. RIXS has revealed that spin excitations persist up to very high doping levels, both in hole- and electron-doped compounds [4,5]. The doping dependence of those magnetic excitations and their inherent character (spin-wave-like rather than Stoner mode) has been extensively characterized in several cuprate families. Moreover the energy selectivity allowed us to discover the reflection peak associated to charge density modulations, initially in underdoped YBCO [6] and, more recently, in optimally doped Bi2212 [7], LSCO and NdBCO. The evidence of persistent short range spin correlation and of ubiquitous charge density fluctuations in cuprates provided by R(I)XS has drastically reopened the debate over the basic mechanisms of HTcS. Finally, the new opportunities in terms of energy resolution, sample orientation control and detection efficiency to be provided by the forthcoming ID32-ERIXS facility at the ESRF and the perspective opened by time-resolved RIXS at the European XFEL will be discussed.

- Fractional diffusion of cold atoms in optical lattices Eli Barkai
Eli Barkai

Fractional calculus is an old branch of mathematics which deals with fractional order derivatives. Recently the Davidson's group (Weizmann) has recorded the spatial diffusion of cold atoms in optical lattices, fitting the results to the solution of a fractional diffusion equation. Within the semi classical theory of Sisyphus cooling we derive this fractional equation and discuss its meaning and its limitations [1,2]. An asymptotically weak friction force, induced by the laser field, is responsible for the large deviations from normal transport theory (and from Boltzmann-Gibbs equilibrium concepts [3]) at least below a critical value of the depth of the optical lattice.

1. E. Barkai, E. Aghion, and D. Kessler From the area under the Bessel excursion to anomalous diffusion of cold atoms Physical Review X 4, 021036 (2014)
2. D. A. Kessler, and E. Barkai Theory of fractional-Levy kinetics for cold atoms diffusing in optical lattices Phys. Rev. Lett. 108, 230602 (2012).
3. A. Dechant, D. A. Kessler and E. Barkai Deviations from Boltzmann-Gibbs equilibrium in confined optical lattices arXiv:1412.5402 [cond-mat.stat-mech] (2014).

Dr. Ariel Amir

Microorganisms such as bacteria and budding yeast are remarkably successful in accurately self-replicating themselves within several tens of minutes. How do cells decide when to divide? How do they control their morphology? I will show how ideas from statistical mechanics and materials science can help answer these questions. In particular, I will show how a stochastic model of cell size control, combined with single cell data, can be used to infer a particular strategy for cell size control in bacteria and budding yeast, and how the theory of elasticity can be utilized to understand the coupling of mechanical stresses and cell wall growth in bacteria

Robotics and artificial intelligence at Bar-Ilan University (A report from the trenches) Prof. Gal Kaminka, Department of Computer Science and Brain Science Research Center, BIU
Prof. Gal Kaminka, Department of Computer Science and Brain Science Research Center, BIU

This informal talk will survey recent advances in robotics and artificial intelligence research, worldwide, and specifically at Bar Ilan University's computer science department. It will present the quiet commercial and scientific revolution enabled by these advances, and introduce little-known, but common challenges, opportunities, and surprises. The talk will highlight milestone achievements in the 12 years since robots firstcame to Bar Ilan, and discuss open challenges that may be of particular interest to physicists:  phase transitions in computational problems; a possible relationship between crowds, magnetism, and social psychology; Asimov's vision of prediction technology (psychohistory), and programmable nano-scale robots. The talk assumes no prior knowledge of computer science or robotics.

Cosmic explosions: A story about paradigms lost Dr. Hagai Perets
Dr. Hagai Perets

The wide diversity of cosmic explosion arise from a variety of complex physical phenomena.  Each one of these cosmic fireworks, be it supernovae, gamma ray burst, stellar collisions or tidal disruptions, is different in nature, but many of them also share many similarities. The study of such explosions had reshaped  science over and over again for thousands of years, breaking the most basic scientific paradigms, building new ones and shedding new light on our understanding of the origin of the universe, its evolution and constituents. I will review the history of supernova research and its breakthroughs and then focus on some of the frontier science done on peculiar types of supernovae discovered in recent years, ranging in orders of magnitude in brightness and time-length. I will discuss the strongly debated progenitors of such cosmic explosions, the main processes involved in their actual production, and their major implications for the evolution of the universe, and I will touch upon the many open questions which they raise. In particular, I will explain how the regular seemingly delicate but shining life of stars eventually leads to their violent explosive death;  how close symbiotic relations between companion stars which exchange materials between them end up in a blasting breakout of a ball of fire, and how all of these can explain our own origins.

Temperature as an Emergent Property of Non-Equilibrium Systems Prof. Emanuele Dala Tore, Department of Physics, BIU
Prof. Emanuele Dala Tore, Department of Physics, BIU

Depicted by P. W. Anderson as "more is different", an emergent phenomenon occurs when a large number of identical objects behaves differently than its original constituents. This situation lays at the core of our understanding of strongly correlated materials, such as insulators and superconductors. However, present theories are often limited to equilibrium systems that can be described by a thermal ensemble at a fixed temperature. How can we extend these ideas to non-equilibrium environments? I will describe a recent approach to the problem, where the temperature is represented as an emergent phenomenon. Although the microscopic degrees of freedom are externally driven and do not equilibrate, the macroscopic properties of the system often display a thermal behavior. Starting from specific case studies, I will present successes and failures of this approach. In my last slide, I will discuss possible relations with the philosophical concept of the messianic era as an emergent property of the universe.

What is the pH of a biomaterial? Prof. Igal Szleifer, Departments of Chemistry and Biomedical Engineering, Northwestern University
Prof. Igal Szleifer, Departments of Chemistry and Biomedical Engineering, Northwestern University

The development of synthetic materials for biorelated applications requires exquisite control of the physical and chemical environment within the materials. In biological systems, mucus represents a family of hydrogels that are responsive to the environment, in particular the pH. In this talk we will discuss pH within synthetic and biological hydrogels. We will start by properly defining the pH in the thermodynamic sense and in terms of the common use of the term. Then, we answer the question what is the pH within a hydrogel and how it relates to the conditions in which it is synthesized and stored. The physical and chemical properties of pH-responsive gels are found to depend on the coupling between acid-base equilibrium, molecular organization and physical interactions. For example, the network’s degree of protonation is not only determined by chemical composition of the bath solution but also by the ability of the polymeric structure to modify the local environment. This coupling results in swelling (or shrinking) that depends on the bath pH and salt concentration. We will discuss examples of different types of hydrogels. For example in bulk systems we predict that the gel pH can be several units smaller than the bath pH depending on the salt concentration. In thin films we will discuss the gradients of protonation state and pH that results from the inhomogeneous distribution of species within the film and how this effect has implications on the effective interactions between proteins (and nanoparticles) and the film. The role of pH and ionic strength on protein adsorption and its implications to chromatography will be discussed. The theoretical predictions can be used as guidelines for the design of responsive gels in a variety of applications ranging from drug delivery systems to tissue engineering scaffolds and they provide for fundamental understanding on the non-trivial behavior of these gels. Moreover, our predictions demonstrate that the chemical state within soft materials may be dramatically different from that of the environment solutions in contact with them. We find than in systems where molecular organization, chemical equilibrium and physical interactions are coupled the behavior of the system is very different from the sum of the parts that form it.

Prof. Dirk Schwalm

Since the formulation of Special Relativity by Albert Einstein more than 100 years, its main ingredient, the space-time symmetry of local Lorentz invariance (LI), forms one of the corner stones of all currently accepted theories describing nature on a fundamental level. Already this fundamental role alone demands thorough experimental affirmation of this symmetry. Further motivation for incessant experimental tests with ever increasing scrutiny comes from theoretical attempts to solve some of the unsettled problems in contemporary physics, such as the reconciliation of quantum theory and general relativity, which allow LI to be violated.   

Within the wealth of LI tests, ‘Ives-Stilwell’ experiments stand out for their large Lorentz boost, which neither depend on sidereal variations nor on a special reference frame. These experiments, which are based on the optical Doppler effect, directly determine the relativistic time dilation effect, one of the most fascinating and at the same time most disconcerting aspects of the space-time symmetry of Special Relativity as it abolishes the notion of absolute time. I will report on our modern versions of this experiment, which involves metastable 7Li+ ions moving with velocities of up to 1/3 of the velocity of light as atomic clocks. The experiments combine ion storage and ion cooling in heavy ion storage rings together with laser induced saturation and optical-optical double resonance spectroscopy to read out the clock frequencies.  Comparing these frequencies with those measured at rest allowed us to verify the relativistic time dilation with unprecedented precision.  

Edvardas Narevicius
There has been a long-standing quest to observe chemical reactions at low temperatures where reaction rates and pathways are governed by quantum mechanical effects or long range interactions. This field of Quantum Chemistry has been dominated, to date, by theory, with almost no experiments. The difficulty so far, has been to realize low enough collisional velocities between neutral reactants, so that the de Broglie wavelength becomes long enough for the quantum wave nature to emerge as a dominating effect. We will discuss how reaction temperatures on the order of several milli Kelvin can be achieved without laser cooling by merging cold and fast molecular and atomic beams. We will show that by controlling the initial electronic state of metastable helium in the ionisation reactions with molecules we can switch reaction mechanism from the universal Langevin behavior into the quantum tunnelling dominated regime.
1. A. B. Henson, S. Gersten, Y. Shagam, J. Narevicius, E. Narevicius, "Observation of Resonances in Penning Ionization Reactions at Sub-Kelvin Temperatures in Merged Beams", Science 338, 234, 2012
2. E. Lavert-Ofir, Y. Shagam, A. B. Henson, S. Gersten, J. Klos, P. S. Zuchowski, J. Narevicius and E. Narevicius, "Observation of the isotope effect in sub-kelvin reactions", Nature Chemistry 6 (4), 332-335, 2014 
Smoluchowski with interactions Prof. Baruch Meerson, Racah Institute of Physics, Hebrew University
Prof. Baruch Meerson, Racah Institute of Physics, Hebrew University

In 1917 von Smoluchowski suggested a simple-minded model of diffusion-controlled binary   
reactions. It consists of an immobile spherical trap of radius R surrounded by a gas of Brownian

particles. The particle flux into the trap mimics the rate of diffusion-controlled reactions. Since

its inception, the Smoluchowski model and its extensions inspired multitudes of studies. The vast

majority of them continued to assume that the particles do not interact with other. Here we extend

this model to a whole class of diffusive gases of interacting particles. Employing the Macroscopic

Fluctuation Theory, we evaluate the probability P(T) that no gas particle hits the trap until a

long but finite time T. We also find the most likely density history of the gas conditional on the

non-hitting. The results crucially depend on the dimension of space d and on the rescaled parameter

  l = R/√D0T where D0 is the gas diffusivity.

- New Tools and Ideas in Particle Physics and Quantum Field Theory Zohar Komargodski
Zohar Komargodski

I will review several recent advances in Particle Physics and Quantum Field Theory. The emphasis is on concepts which are applicable beyond perturbation theory. For example, we will discuss the  Entanglement Entropy of the vacuum, the number of light excitations, the relation to gravity, and the symmetries of Quantum Field Theory.


Pre-colloquium: Order, Disorder, Symmetry and Complexity Prof. Daniel Stein, Depts. of Physics and Mathematics, NYU
Prof. Daniel Stein, Depts. of Physics and Mathematics, NYU

One of the deepest scientific questions we can ask is, How might complexity arise? That is, starting from simple, undirected processes subject to physical and chemical laws, how could structures with complex shapes and patterns arise, and even more perplexing, what processes could give rise to living cells, and how might they then organize themselves into complex organisms, leading ultimately to such things as brains, consciousness, and societies? We are far from answering these questions at almost any level, but they have attracted increasing attention in the scientific community, and some initial headway has been made. The basic problem can be reframed as one involving the self-organization of microscopic constituents into larger assemblies, in such a way that the process leads to an increase of information, the creation of new patterns, and eventually increasing hierarchical levels of complex structure. The key to understanding these processes cannot be found in any single (natural or social) scientific field but rather in collaborations that cross many disciplinary boundaries. Although we are still at the initial stages of inquiry, new and interesting approaches and points of view have arisen. In this talk I present one that arises from the point of view of physics. We start by describing the (well-understood) phenomenon of matter organizing itself into simple ordered structures, like crystals and magnets, and then explore how our ideas are affected when we consider the effects of randomness and disorder, pervasive in the physical world. We will see that randomness and disorder are, paradoxically, essential for more ordered, complex structures to arise. Using these ideas, we provide some hints (but only hints) as to how we can gain a handle on issues related to the increase of complexity. Underlying all of our considerations is the notion of symmetry in physics: where it comes from and how matter "breaks" its inherent symmetry to create new information and ever-increasing complexity.

Higgs mode and universal dynamics near quantum criticality Prof. Daniel Podolsky, Department of Physics, Technion
Prof. Daniel Podolsky, Department of Physics, Technion

The Higgs mode is a ubiquitous collective excitation in condensed matter systems with broken continuous symmetry.  It plays a role analogous to the Higgs boson in particle physics.  Its detection is a valuable test of the corresponding field theory, and its mass gap measures the proximity to a quantum critical point. However, since the Higgs mode can decay into low energy Goldstone modes, its experimental visibility has been questioned. In this talk, I will show that the visibility of the Higgs mode depends on the symmetry of the measured susceptibility. I will also present an analysis of the evolution of the Higgs mode upon approach to the Wilson-Fisher fixed point in 2+1 dimensions and demonstrate that the Higgs mode survives as a universal resonance in the scalar susceptibility arbitrarily close to the quantum critical point. I will discuss the implications of these results for experiments on lattice Bose condensates and thin film superconductors near the Mott insulator to superfluid transition.

Biological self-organization as an interplay between stability and flexibility Prof. Yoav Soen, Dept. of Biological Chemistry, Weizmann Institute
Prof. Yoav Soen, Dept. of Biological Chemistry, Weizmann Institute

The development of organisms must be robust enough to maintain adaptive patterns and flexible enough to enable coping with fluctuating external and internal conditions (e.g. environmental, genetic, epigenetic and symbiotic perturbations). How this tension between stability and flexibility is handled and the potential implications of this co-existence to establishment of new adaptations are not clear.

We are addressing these questions by studying stress-induced induction and inheritance of altered developmental patterns in flies. We identified epigenetic and symbiotic-mediated mechanisms which promote increased developmental flexibility under stress and contribute to non-Mendelian transfer of influences across generations.

I will present these findings and discuss their potential implications for bridging ecological and evolutionary processes.

New Insight into an Old Puzzle – the Hofmeister Universality Probed by AFM Prof. Uri Sivan, Dept. of Physics, Technion
Prof. Uri Sivan, Dept. of Physics, Technion

Hofmeister and his PhD student, Lewith, discovered 126 years ago that different ions destabilize proteins to a markedly different extent. They ranked ions according to their precipitation power in a series known today as the Hofmeister series. Since then, scientists discovered dozens of additional ion-specific phenomena including surface tension, ion transport through biological and inanimate membranes and channels, colloidal stability, enzyme activity, bacterial growth, and more. Remarkably, with only few exceptions, the same Hofmeister series was discovered to characterize the effect of ions on this myriad of ostensibly different phenomena, strongly suggesting the existence of an underlying common microscopic mechanism. The universality reflected in the Hofmeister series has turned this problem into one of the fundamental puzzles in biophysics and the physics of soft matter. The search for an underlying mechanism has motivated extensive research and important discoveries but the Hofmeister universality proved more challenging than naively anticipated.

In the past few years, our lab has been employing Atomic Force Spectroscopy to measure the effect of different ions on the short range force acting between two surfaces in solution. The full force vs. distance curves obtained this way gave significant new insight into the Hofmeister puzzle and suggested, in combination with recent optical measurements, a surprisingly simple picture of the underlying physics. 

Probing molecular-ion beams with intense few-cycle laser pulses – two-color controlled dissociation Itzik Ben-Itzhak J.R. Macdonald Laboratory, Department of Physics, Kansas State University
Itzik Ben-Itzhak J.R. Macdonald Laboratory, Department of Physics, Kansas State University

See attached file.

Emerging Frontiers in Ultrafast Multidimensional NMR and MRI Prof. Lucio Frydman, Department of Chemical Physics, Weizmann Institute
Prof. Lucio Frydman, Department of Chemical Physics, Weizmann Institute

Magnetic resonance provides a prime tool for elucidating molecular structures in its spectroscopic (NMR) mode, and for the non-invasive mapping of objects in its imaging (MRI) mode. While entailing very different applications, the basic quantum foundations of both NMR and MRI are common. So are many of the techniques used in either molecular elucidations and/or images –and foremost among these the Nobel-winning proposition of multidimensional NMR/MRI. While these acquisitions take order-of-magnitude longer acquisition times than 1D traces, we have recently developed a scheme enabling the acquisition of arbitrary multidimensional NMR spectra and/or images (MRI) within a single scan.  This is by contrast to the hundreds or thousands of scans that are usually needed to collect this kind of data. Provided that the target molecule's signal is sufficiently strong, the acquisition time of NMR/MRI scans can thus be shortened by several orders of magnitude.  This new “ultrafast” methodology is compatible with existing multidimensional pulse sequences and can be implemented using conventional hardware. The manner by which the spatiotemporal encoding of the NMR interactions —which is the new physical principle underlying these new protocols— proceeds in these experiments, will be summarized. The new horizons that are opened by these protocols will also be exemplified with a variety of NMR and MRI projects we are currently involved in in fields of chemistry, biophysics, biology and medicine. 

Quantum nanomagnetism and related phenomena Prof. Javier Tejada, Department of Physics, University of Barcelona
Prof. Javier Tejada, Department of Physics, University of Barcelona

In my talk I will review the experimental work done in the field of nanomagnets, emphasizing the description of quantum relaxation in magnetic nanoparticles and resonant spin tunneling in molecular magnets. I will start introducing the concepts of both exchange energy and magnetic anisotropy and the static and dynamic magnetic properties of nanoparticles. Then I will move to comment on the effect of quantum tunneling of magnetic poles in magnetic nanoparticles; quantum magnetic relaxation  and the so called quantum resonant spin tunneling.  The next step will be to explain phenomena related to spin tunneling such as quantum magnetic deflagration, the emission of superradiance by the magnetic flame and the possible use of nanomagnets as qubits. To finish, I will comment on the appearance of a new force of quantum origin in molecular magnets.



Disecting transcription regulation using single molecule imaging Professor Xavier Darzacq, Institute of Biology, ENS Paris
Professor Xavier Darzacq, Institute of Biology, ENS Paris

While membranes do not compartmentalise the nucleus, it shows a complex organisation at many scales. Spatial organisation of chromatin and transcription factors can modulate nuclear functions and in order to study this relation, we have developed methods to localise proteins and mRNAs at the single molecule level and with spatial resolutions in the range of a few nanometers (modifications and improvements of PALM, sptPALM and STORM using adaptive optics). Moreover, proteins move throughout the nucleus by diffusion, transiently and repetitively contacting their target sites. While DNA has been reported as a guide facilitating target search in the cell by restricting 3 dimensional explorations to a 1 dimensional search, such exploration modes were not envisioned mediated by protein-protein interactions. I will discuss chromatin and RNA polymerase II organisation in the nucleus as well as mechanisms guiding proteins to their targets in the nucleoplasm. 

Transmission eigenchannels, the density of states and intensity profiles inside opaque media Prof. Azriel Genack, Department of Physics, Queens Colledge, CUNY
Prof. Azriel Genack, Department of Physics, Queens Colledge, CUNY

We find a single expression for the average intensity profile of eigenchannels of the transmission matrix inside single and multichannel random media for quasi-ballistic, diffusive and localized waves. The intensity profiles are built upon the simple form of the completely transmissive channel and depend only upon the transmission eigenvalue, τ, the sample length and the localization length. We show that eigenchannel intensity profiles are related to the auxiliary localization lengths introduced by Dorokhov to parameterize τ. The integral of the spatial intensity distribution over the sample volume for unity incident flux , which is the contribution of each eigenchannel to the density of states (DOS), is equal to the derivative of the average phase of the transmission eigenchannel with angular frequency of the incident radiation. The sum of the eigenchannel DOS over all eigenchannels gives the density of states (DOS) which controls spontaneous and stimulated emission and wave localization. This is demonstrated in microwave experiments in the equivalence of spectra of the DOS determined from a decomposition of the wave into transmission eigenchannels and quasi-normal modes.

Statistical Physics of Pure Barkhausen Noise Prof. Itamar Procaccia, Dept. of Chemical Physics, Weizmann Institute
Prof. Itamar Procaccia, Dept. of Chemical Physics, Weizmann Institute
We discuss a model metallic glass in which Barkhausen Noise can be studied in exquisite detail, free of thermal effects and of the rate of ramping of the magnetic field. The mechanism of the jumps in magnetic moment that cause the Barkhausen Noise can be fully understood as consecutive instabilities where an eigenvalue of the Hessian matrix hits zero, leading to a magnetization jump $\Delta m$ which is simultaneous with a stress and energy changes $\Delta \sigma$ and $\Delta U$ respectively. Contrary to common belief we find no ``movements of magnetic domain boundaries" across pinning sites, no fractal domains, no self-organized criticality and no exact scaling behaviour. We present a careful analysis of the statistical properties of the phenomenon, and show that with every care taken this analysis is tricky, and easily misleading. Without a guiding theory it is almost impossible to get the right answer for the statistic of Barkhausen Noise. We therefore present an analytic theory, showing that the probability distribution function (pdf) of Barkhausen Noise is not a power law times an exponential cutoff. On the basis of the theory we explain why standard methods to extract the form of the pdf are likely to fail, as indeed happened until now.
Universal Dynamics and Topological Order in Many-Body Localized States Prof. Ehud Altman, Department of Physics of Condensed Matter, Weizmann Institute of Science
Prof. Ehud Altman, Department of Physics of Condensed Matter, Weizmann Institute of Science

It has been argued recently that, through a phenomenon of many-body localization, closed quantum systems subject to sufficiently strong disorder would fail to thermalize. In this talk I will discuss the nature of the dynamics in the localized state. I will show that rather than being a dead state, the localized phase supports highly non trivial modes of quantum dynamics. Most spectacularly, many-body localization can facilitate the existence of topological order in the entire many-body spectrum rather than in the ground state alone. I will demonstrate with a concrete model of a quantum magnet how this leads to protected quantum-bits that retain perfect coherence even when the system is at arbitrarily high energy.

Deciphering codes in DNA sequences Prof. Eran Segal, Dept. of Mathematics and Computer Science, Weizmann Institute
Prof. Eran Segal, Dept. of Mathematics and Computer Science, Weizmann Institute

Much of the phenotypic differences among people is attributable to genetic variation in regulatory regions that affect the activity levels of the various genes. However, without a ‘regulatory code’ that informs us how DNA sequences determine gene activity levels, we cannot predict which sequence changes will affect gene activity levels, by how much, and by what mechanism. To address this challenge, we developed a high-throughput method for constructing libraries of thousands of fully designed regulatory sequences and measuring their gene activity levels in parallel, within a single experiment, and with an accuracy similar to that obtained when each sequence is constructed and measured individually. Using this ~1000-fold increase in the scale with which we can study the effect of sequence on gene activity, we designed and measured the activity levels of libraries in which we systematically perturbed different sequence elements. Our results provide several new insights into principles of gene activity regulation, bringing us closer towards a mechanistic and quantitative understanding of how gene activity levels are encoded in DNA sequence.

Strongly correlated systems in few-body land Prof. Chris H. Greene, Department of Physics, Purdue University, IN, USA
Prof. Chris H. Greene, Department of Physics, Purdue University, IN, USA

This colloquium will discuss some of the nonperturbative
physics that occurs when a few particles interact strongly, stressing
low-energy phenomena where one needs to go beyond perturbation theory.
Some of the problems of recent interest include the recombination of 3
or 4 or even 5 ultracold atoms to form molecules, a key process that
tends to eject atoms and cause losses from a Bose-Einstein condensate.
Resonances in this system are connected with the intriguing Efimov
effect.  Another recent interest has been the field of artificial gauge
potentials in cold atom physics, where an appropriate laser dressing of
neutral atoms causes them to behave as though they were charged
particles in a magnetic field or even with artificial spin-orbit
coupling.  I will discuss recent developments that allow the theory to
treat such systems quantitatively and also enable qualitative intuition
to be developed, in the context of recent experiments.

Probing molecular-ion beams with intense few-cycle laser pulses – two-color controlled dissociation Prof. Itzik Ben-Itzhak, Department of Physics, Kansas State University
Prof. Itzik Ben-Itzhak, Department of Physics, Kansas State University

We have studied laser-induced fragmentation of molecular-ion beams using coincidence 3D momentum imaging, with direct separation of all the reaction products measured simultaneously. These measurements provide detailed kinetic energy release and angular distributions of the different fragmentation processes. We mainly focus on the fundamental H2+ and H3+ molecules (in 5-50 fs laser pulses having 1012-1016 W/cm2 peak intensity) as models for more complex systems, and at times we do explore more complex molecules such as O2+ and CO2+.

In this talk, we will discuss electron localization on specific nuclei during strong-field dissociation of molecular-ion beams which is controlled by the relative phase between the 790 and 395 nm components of an ultrashort laser pulse.

In addition, clear experimental and theoretical evidence for the intriguing zero-photon dissociation (ZPD) process of H2+ will be presented. The key role of the laser-pulse bandwidth and chirp on ZPD control will be discussed. Moreover, we will explore control over the final dissociation product of HD+, either H+ + D or H + D+ – usually referred to as channel asymmetry.

Leptogenesis Prof. Yuval Grossman, Department of Physics, Cornell University, NY USA
Prof. Yuval Grossman, Department of Physics, Cornell University, NY USA

There are two open questions in physics which seem
unrelated. The first is why is there only matter around us? The second
is how neutrinos acquire their tiny masses? It turns out that these
two open questions may be related. That is, the same mechanism that
gives neutrino masses can also generate a universe without
anti-matter. In this talk I will explain the connection between these
two issues and describe the on-going theoretical and experimental
efforts in understanding them.

Thermodynamics of strongly correlated gases Prof. Frédéric Chevy, Ecole Normale Supérieure, Paris, France
Prof. Frédéric Chevy, Ecole Normale Supérieure, Paris, France

The understanding of the properties of strongly correlated quantum systems is one of the most challenging open problems in modern physics, since it is relevant to fields as different as condensed matter, astrophysics or nuclear physics. Using the latest techniques of manipulation of ultracold vapors, it is now possible to probe the quantum many body problem using the tools of atomic physics. In this talk, I will show that it is possible to engineer model experimental systems reproducing faithfully some of the most popular hamiltonians used in theoretical physics. I will illustrate this on the study of the thermodynamic properties of strongly correlated gases that can now be benchmarked accurately using advanced experimental and theoretical techniques.

Many-body physics with quantum gases in disorder Prof. G.V. Shlyapnikov, LPTMS, Université Paris Sud, Bat. 100, 91405 Orsay, France and University of Amsterdam, The Netherlands
Prof. G.V. Shlyapnikov, LPTMS, Université Paris Sud, Bat. 100, 91405 Orsay, France and University of Amsterdam, The Netherlands

It is commonly accepted that there are no phase transitions in one-dimensional (1D) systems at a finite temperature, because long-range correlations are destroyed by thermal fluctuations. I will demonstrate that the 1D gas of short-range interacting bosons in the presence of disorder can undergo a finite temperature phase transition between two distinct states: fluid and insulator. None of these states has long-range spatial correlations, but this is a true albeit non-conventional phase transition because transport properties are singular at the transition point. In the fluid phase the mass transport is possible, whereas in the insulator phase it is completely blocked even at finite temperatures. Thus, it is revealed how the interaction between disordered bosons influences their Anderson localization. This key question, first raised for electrons in solids, is now crucial for the studies of atomic bosons where recent experiments have demonstrated Anderson localization. I then consider weakly interacting bosons in a 1D quasiperiodic potential (Aubry-Azbel-Harper model), where all single-particle states are localized if the hopping amplitude in the primary lattice is smaller than half the amplitude of the secondary incommensurate lattice. The interparticle interaction may lead to the many-body localization-delocalization transition, and I will show the finite temperature phase diagram. Counterintuitively, in a wide temperature range an increase in temperature requires a higher interaction strength for delocalization and thus favors the insulator state. In this sense, we have an object that ''gets frozen'' under an increase in temperature.

The extra-solar planets: new worlds (very) different from our own Solar system Prof. Tsevi Mezeh, School of Physics and Astronomy, Tel-Aviv University
Prof. Tsevi Mezeh, School of Physics and Astronomy, Tel-Aviv University

The talk will review the history of the discovery of the
extra-solar planets, with emphasis on the recent findings
Kepler and CoRoT space missions. I will show that we have found
systems that have features different than almost all the
characteristics of our own planetary system.

The LHC, Dark Matter and Beyond: Speculations on the Future of Particle Physics Prof. Tomer Volansky, School of Physics and Astronomy, Tel Aviv University
Prof. Tomer Volansky, School of Physics and Astronomy, Tel Aviv University

The discovery of the Higgs boson at the LHC is one of the greatest scientific achievements this centuries.   Still, despite the anticipation, no unambiguous signal of physics beyond the Standard Model of particle physics has been observed at colliders or at experiments that search for dark matter, to date.   In this talk I will review the current theoretical and experimental state of particle physics, in light of dark matter experiments and the LHC results.  I will then discuss the near future plans in the field and shortly speculate on the various possible outcomes and their implications to particle physics.

Transport by he Nuclear Pore Complex: simple physics of a complex biomachine Professor Anton Zilman, Department of Physics, Uniersity of Toronto
Professor Anton Zilman, Department of Physics, Uniersity of Toronto

Abstract: Nuclear Pore Complex (NPC) is a biological “nano-machine” that controls the  transport between the cell nucleus and the cytoplasm and is involved in a large number of regulatory processes in the cell. It is a remarkable device that combines selectivity with robustness and speed. Unlike many other biological nano-channels, it functions without direct input of metabolic energy and without transitions of the gate from a ‘closed’ to an ‘open’ state during transport. The key, and unique, aspect of transport is the interaction of the cargo-carrying transport factors with the unfolded, natively unstructured proteins that partially occlude the channel of the NPC and its nuclear and cytoplasmic exits. Recently, the Nuclear Pore Complex inspired creation of artificial selective nano-channels that mimic its structure and function for nano-technology applications.

Mechanistic understanding of the transport through the Nuclear Pore Complex, and in particular its selectivity is still lacking. Conformational transitions of the unfolded proteins of the NPC, induced by the transport factors, have been hypothesized to underlie the transport mechanism and its selectivity. These conformational changes are hard to access in vivo; they have been investigated in vitro, generating apparently contradictory results. I will present a theoretical framework that explains the mechanism of selectivity of transport through the NPC and related artificial nano-channels. The theory provides a general physical mechanism for selectivity (even in presence of noise) based on the differences in the interaction strength of the transported molecules with the polymer-like unfolded proteins within the NPC. The theoretical predictions have been verified in experiments with bio-mimetic molecular nano-channels.

Quantum Optics with Semiconductor Quantum Dots Prof. David Gershoni, Department of Physics, Technion
Prof. David Gershoni, Department of Physics, Technion

I will discuss recent  studies of single semiconductor quantum dots as excellent sources of single and entangled photons. In particular I will discuss and demonstrate methods to fully control the spin state of quantum dot confined carriers and to entangle between their spin states and the polarization states of emitted single photons.

From Bacterial Communication to Cyber-war on Cancer Prof. Eshel Ben-Jacob, Dept. of Physics, Tel-Aviv University
Prof. Eshel Ben-Jacob, Dept. of Physics, Tel-Aviv University

Cancer continues to elude us. Metastasis, relapse and drug resistance are all still poorly understood and clinically insuperable. Evidently, the prevailing paradigms need to be re-examined and out-of-the-box ideas ought to be explored. Drawing upon recent discoveries demonstrating the parallels between collective behaviors of bacteria and cancer, we present a new picture of cancer as a society of smart communicating cells. There is growing evidence that cancer cells, much like bacteria do, rely on advanced communication, social networking and cooperation to grow, spread within the body, colonize new organs, relapse and develop drug resistance. We address the role of communication, cooperation and decision-making during tumoregenesis. This leads to a new picture of cancer cell migration, metastasis colonization and cell fate determination. We reason that the new understanding calls for “cyber war” on cancer – the developments of drugs to target cancer communication and control. 

Universal few-body physics with ultracold atoms Prof. Lev Khaykovich
Prof. Lev Khaykovich

Few-body systems with resonantly enhanced two-body interactions display universal properties in the sense that they are independent of the details of the short-range interaction potential. The central paradigm in the three-body domain, predicted in the early 1970s by V. Efimov, is associated with the infinite ladder of weakly bound states with discrete scaling invariance. This curious prediction avoided experimental verification in different systems for decades, and only recently and exclusively surrendered to ultracold atoms. After giving a general introduction into Efimov scenario, I will describe the remarkable progress in its experimental investigation with the emphasize to our studies performed with ultracold lithim gas

Time-multiplexed entanglement between many photons Prof. Hagai Eisenberg, Racah Institute, HUJI
Prof. Hagai Eisenberg, Racah Institute, HUJI

The generation of entanglement between more than two particles is a major challenge of all physical realizations. Single photons are one of the most promising realizations of quantum bits (qubits), as they are easily manipulated and preserve their coherence for long times. Quantum information can be stored in many different degrees of freedom of the photons. Only recently, eight photons were entangled in a single state through their polarization degree of freedom. The main difficulties in increasing this number are the elaborated setups required and the low rates of state production. I will present a novel and simple scheme that can in principle generate entanglement between any number of photons from a single setup. Because of some special symmetries of this setup and the fact that it combines photons in different paths as well as from different times, there are some surprising consequences that challenge our understanding of non-locality and the measurement of quantum states. A roadmap for even better photon entanglement sources that are suitable for quantum computation will also be presented.

The Birth of Quantum Physics - Boltzmann, Planck, Einstein, Nernst, and others Prof. Rudolf P. Huebener, Eberhard Karls Universität, Tübingen
Prof. Rudolf P. Huebener, Eberhard Karls Universität, Tübingen

At the end of the 19th century due to the rapid growth of artificial illumination there developed a need for quantitative optical data and relevant standards. Hence, in the optical laboratory of the Physikalisch-Technische Reichsanstalt in Berlin the spectral distribution of the light intensity was measured over a large frequency range. The new data could not be explained in terms of the existing models. Between October and December 1900 Max Planck arrived at his famous radiation law based on Boltzmann’s probabilistic entropy expression. As a key novelty Planck introduced the quantization of the radiation energy in terms of the discrete energy elements hν, with the universal constant h. Whereas Planck did not accept the full impact of the new quantum physics for nearly 10 years, it was Albert Einstein with his light quanta in 1905 and his quantized lattice vibrations in 1906, and a few years later Walther Nernst with his specific heat measurements, who strongly pushed the new ideas about the quantum physics. 

Diametric strategies for ultra-efficient photovoltaics Professor Jeffrey Gordon, Department of Solar Energy and Environmental Physics , Ben-Gurion University
Professor Jeffrey Gordon, Department of Solar Energy and Environmental Physics , Ben-Gurion University

Recent advances from two diametric approaches for realistically approaching the fundamental limits to solar cell conversion efficiency, which follow from basic thermodynamics, will be presented. One relates to a new concept in cell architecture for concentrator photovoltaics, with the possibility of using exclusively indirect bandgap semiconductors (including Si and Ge) at irradiance values of thousands of suns. The second constitutes the first experimental demonstration of performance enhancement by recycling photon emission from high-efficiency non-concentrator (one-sun) solar cells. An analysis of the results points to roadmaps for future improvements.

Imaging and Analysis of Hebrew First Temple Period Ostraca Professor Eli Piasetzky, Department of Physics, Tel-Aviv University
Professor Eli Piasetzky, Department of Physics, Tel-Aviv University

An ostracon is a piece of pottery or stone that contains writing. We have been studying ostraca written in the ancient Hebrew alphabet from the first Temple era. The writing is in ink on a clay ceramics background, and is sometimes illegible and very difficult to decipher. I will describe our use of modern technologies to document and improve reading of these ancient inscriptions.

      The discipline of palaeography studies the morphology of the letters, their diachronic development over time, and their synchronic variations at a given time. This has been traditionally carried out manually with subjective bias. I will also describe our efforts to introduce the latest developments in image processing and artificial intelligence into this field. Our objective is to date the writing, identify the development of the Hebrew alphabet, find differences between writings from the kingdoms of Israel and Judah, and  to distinguish between different scribes in the individual inscriptions.

Professor Sorin Solomon, Racah Institute, HUJI

In statistical physics the emergence of large scale collective phenomena out of local interactions between simple agents takes place in general only for very special (zero measure) / critical values of the parameters (temperature, pressure, etc).

Yet in nature collective objects and their large scale dynamics are ubiquitous features dominating our daily experience.
Each of the last decades proposed a different generic mechanism for the emergence of macroscopic complex dynamics out of local microscopic laws.
Nowadays it seems that most of the instances in which microscopic events are promoted to macroscopic changes are related to some form of autocatalytic process.
Identifying the relevant autocatalytic process allows one to gain understanding and control on the seemingly messy empirical systems.
I will review some of the instances in which the resulting models were analytically tractable and in which the theoretical predictions were confirmed by the data.
Spin Filtering: how to write and read quantum Prof. Amnon Aharony, Ben Gurion and Tel Aviv Universities
Prof. Amnon Aharony, Ben Gurion and Tel Aviv Universities

Quantum computing requires the ability to write and read quantum information on the spinors of electrons. This work considers mobile electrons, which move through mesoscopic (or molecular) quantum networks (made of quantum wires or of arrays of quantum dots). Combining spin-orbit interactions, whose strength can be tuned by external gate voltages, and the Aharonov-Bohm flux, which can be tuned by an external magnetic field, one can manipulate the properties of such networks, so that the outgoing electrons are polarized along a desired direction. This amounts to 'writing' the desired information on the spinor of the electrons. Given a beam of polarized electrons, the charge conductance of the same network depends on their polarization, allowing 'reading' the qubit information. Specific results will be presented for a simple closed interferometer [1]. The talk will also report on more recent work:

(a) The above filtering is robust against leaking of electrons, in an open interferometer [2]. (b) Filtering can also be achieved for a single one dimensional chain which has spin-orbit interactions, when the chain vibrates in the transverse direction [3].


[1] A. Aharony, Y. Tokura, G. Z. Cohen, O. Entin-Wohlman, and S. Katsumoto, Filtering and analyzing mobile qubit information via Rashba-Dresselhaus- Aharonov-Bohm interferometers, Phys. Rev. B 84, 035323 (2011);(arXiv:1103.2232)

[2] S. Matityahu, A. Aharony, O. Entin-Wohlman and S. Katsumoto, Robustness of spin filtering against current leakage in a Rashba-Dresselhaus-Aharonov-Bohm interferometer, Phys. Rev. B 87, 205438 (2013); (arXiv:1302.6772)

 [3] Work with R. I. Shekhter and O. Entin-Wohlman.

There is a wide interest in the development of optical fibers for the mid - IR (i.e. 3-30mm).  AgClBr crystals are extruded in our laboratory to form fibers, which are flexible, non-toxic, non-hygroscopic and highly transparent in the mid-IR.  These silver halide fibers have made it possible to carry out advanced research and development, which will be discussed in this talk:

(1)  Non - contact fiberoptic thermometry.

(2)  Laser power transmission through IR fibers (e.g. laser cutting or heating).

(3)  Laser bonding of tissues - clinical studies.

(4)  Fiberoptic evanescent wave spectroscopy and its applications:

  1. Environmental protection (e.g. monitoring of pollution in water and soil).
  2. Homeland Security (e.g. online monitoring of poisons in water).
  3. Early diagnosis of diseases, such as cancer – clinical studies.

(5)  Periodic structures of IR Fibers:

a.   Thermal imaging through ordered bundles of fibers.

b.   Novel photonic crystal fibers.

(6)   Single mode fibers and waveguides for mid - IR astronomy (e.g. nulling interferometry).

(7)  Doped AgClBr crystals and fibers for mid - IR amplifiers and lasers (e.g. countermeasures against shoulder launched missiles).

(8)  Near-field scanning mid-IR microscopy with a sub-wavelength resolution (e.g. the study of individual living cells or of individual components in integrated electronic circuits).


From polymer rings to genome folding Professor Alexander Grosberg, Center for Soft Matter Physics, New York University
Professor Alexander Grosberg, Center for Soft Matter Physics, New York University

Each cell of our body contains two meters of DNA stored in ten micrometers nucleus. Why does not it tangle? In the talk, recent numerical, theoretical, and experimental advances in the field will be reviewed in connection to one another. The melt of non-concatenated rings will be presented as a workhorse theoretical model to explain many relevant features, including chromosome territoroes and experimentally observed scaling of contact probabilities.

Friction, classical and quantum Prof. Emil Polturak, Faculty of Physics, Technion
Prof. Emil Polturak, Faculty of Physics, Technion

Friction at the macroscopic scale continues to be a thriving research area, in accordance with its undisputed importance in our life. At the microscopic scale, experiments show that in some cases, the friction between two solid surfaces can be vanishingly small. An open problem is whether friction between macroscopic bodies can result from quantum fluctuations. Recent experiments, in which the friction between two slabs of a quantum solid was actually measured, offer a way to answer this question.

Stochastic Oscillator With Random mass : New Type of Brownian Motion Prof. Moshe Gitterman, Dept. of Physics, BIU
Prof. Moshe Gitterman, Dept. of Physics, BIU

The model of stochastic oscillator subject to additive random force, which includes the Brownian motion, is widely used for analysis of different phenomena in physics, chemistry, biology, economics and social science. As a rule, by the appropriate choice of units one assumed that the particle's mass is equal to unity. However, for the case of an additional multiplicative random force, the situation is more complicate. As we show, for the cases of random frequency or random damping, the mass cannot be excluded from the equations of motion, and, for example, besides the restriction of the size of Brownian particle, some restrictions exist also of its mass. In addition to these two types of multiplicative forces, we consider the random mass, which describes, among others, the Brownian motion with adhesion. The fluctuations of mass are modelled as a dichotomous noise, and the first  two moments of coordinates show non-monotonic dependence on the parameters of oscillator and noise, In the presence of an additional periodic force an oscillator with random mass is characterized by the stochastic resonance phenomenon, when the appearance of noise increases the input signal.

Worm sleep: a universal behavior meets a simple model system Professor David Biron, Department of Physics, University of Chicago
Professor David Biron, Department of Physics, University of Chicago

All animals sleep, or do they? This question remains controversial. If sleep is truly universal to the animal kingdom then even the simplest model animal, the hydrogen atom of neuroscience if you will, should sleep. The nematode Caenorhabditis elegans develops through four larval stages before it reaches adulthood. At the transition between stages and before it molts, i.e., synthesizes a new exoskeleton and sheds the old one, it exhibits a quiescent state termed lethargus. In a seminal paper in 2008, David Raizen has demonstrated that lethargus bears several similarities to sleep. The talk will describe our contributions to establishing C. elegans lethargus as a model for sleep, as well as related topics. We approach the problem with a combination of behavioral, computational, genetic, physiological and optical techniques. Examples of behavioral dynamics associated with lethargus include the nematode’s hockey stick-like posture and the maneuver that it facilitates, non-Markovian locomotion dynamics (micro-homeostasis) and the modulation of global locomotion states over long timescales. As time permits, the modulation of neuronal activity associated with lethargus, the role of serotonin in sleep-wake transitions, and a novel nematode nociceptor will be briefly discussed.

Gad Koren, Faculty of Physics, Technion

A simple overview of topological insulators (TI) and topological superconductors (TSC) will be given. TI are bulk insulators with surface conductance. They are robust against disorder and decoherence, and therefore interesting for quantum computing. A TSC can be realized when superconductivity is induced in a TI by the proximity effect with a conventional s-wave superconductor. TSC junctions with a normal metal are predicted to have zero bias conductance peaks in their conductance spectra which originate in Majorana fermions (MF). These MF states might be the basic units of a future quantum computer. Recent experimental results will be presented and discussed in the context of TSC and MF.

Soft machines and the mechanics of growing helical strips Prof. Eran Sharon, The Racah Institute of Physics, HUJI
Prof. Eran Sharon, The Racah Institute of Physics, HUJI


Many natural structures are made of soft tissue that undergoes complicated shape transformations as a result of the distribution of local active deformation of its "elements". Currently, the ability of mimicking this shaping mode in manmade structures is poor.

I will present some results of our study of actively deforming thin sheets.

We formulated a covariant elastic theory from which we derive an approximate 2D plate/shell theory for sheets with intrinsic incompatible metric and curvature tensors. With this theory we study selected cases of special interest.

Experimentally, we use environmentally responsive gel sheets that adopt prescribed metrics upon induction by environmental conditions. With this system we study the shaping mechanism in different cases of imposed metrics and curvature.

I will focus on different mechanisms that form helical ribbons and will show how the mechanism of seed pod opening is related to shape selection in self assembled chiral macromolecules.

Probing the physics of complex oxide interfaces with scanning SQUID microscopy Dr. Beena Kalisky, Department of Physics, Bar-Ilan University
Dr. Beena Kalisky, Department of Physics, Bar-Ilan University
Complex oxide materials have a broad range of functionality such as ferromagnetism, piezoelectricity, and superconductivity. When combinations of complex oxides are grown as heterostructures, changes in the local electronic-structure at the interface can create new electronic phases that cannot exist in either parent material. One example is the interface formed by growing LAO on STO. Though both materials are insulators, the interface between them shows conductivity, superconductivity and even magnetism.

In the LAO/STO system we discovered nanoscale patches of magnetism coexisting with superconductivity. An outstanding question is what controls the magnetism, and how it relates to the conductivity and superconductivity. I will describe our efforts to answer these questions, by mapping the landscape of ferromagnetism, superconductivity and conductivity with scanning SUQID microscopy. I will focus on our studies of current flow at the interface from a local point of view. We found that at low temperatures the current flows in highly conductive channels that are related to STO tetragonal domain structure. The interplay between substrate domains and the interface provides an additional mechanism for understanding and controlling the behaviors of heterostructures.
Einstein's Roadmap to General Relativity Professor Hanoch Gutfreund, Center for Brain Sciences, HUJI
Professor Hanoch Gutfreund, Center for Brain Sciences, HUJI


After completing his Special Theory of Relativity, Einstein felt a compelling need to generalize the principle of relativity from inertial to accelerated motion and to include gravitation in the process. He struggled with this task for eight years. At an early stage he was fascinated by the idea that acceleration is equivalent to gravitation, which led him to differential geometry as the basic tool for formulating the new theory. What followed was a series of misinterpretations, wrong paths and simple errors until the "happy end" in November 1915. In 1916, Einstein wrote to Lorentz: "The series of my papers on gravitation is a chain of erroneous paths, which nevertheless gradually brought me closer to my goal."

The lecture will describe this intellectual scientific odyssey.

An ant of few words: group communication with limited vocabulary Dr. Offer Feinerman, Department of Physics, Weizmann Institute
Dr. Offer Feinerman, Department of Physics, Weizmann Institute

Biological individuals often interact to form cooperative societies that have functional advantages.
How the specifics of these interactions constrain collective performance is not well
understood. In this context, we study how desert ants inform each other about the presence
of food. We use automated tracking to generate a large data-base of ant trajectories and interactions
that provides us with sufficient statistics to empirically estimate the efficiency of their
communication. This is done, quantitatively, by calculating the information theoretical channel
capacity of the ants' pairwise interactions. We find that this channel is noisy to a degree
that makes it difficult for ants to tell between a recruiter reporting about food and a random
collision within the dark nest environment. To distinguish these ambiguous signals the colony
must therefore perform error-correcting on the level of the group. We demonstrate that the ants
accomplish this by exhibiting strict control of when to transmit a message and when to respond
to received information. This control leads a collective process that couples negative and positive
feedbacks and ensures reliable colony performance. Thus, the ants need no language, but
just one aptly used "word" pronounced with conviction inside a noisy environment.

Probing cosmological physics with large scale motions of galaxies Professor Adi Nusser, Faculty of Physics, Technion
Professor Adi Nusser, Faculty of Physics, Technion

The standard cosmological model based on dark energy, standard gravity,
and cold dark matter as the driver for structure formation has passed
important observational tests related to the present distribution of
matter on large scales (larger than a few 10s of Megaparsecs). It will
be argued that deviations from the standard model can be further probed
through signatures of the large scale motions (deviations from pure
Hubble flow) of galaxies. Some constraints on f(R) and DGP gravity will
be described using motions of galaxies in the nearby Universe.
It will be shown how future surveys of ~ a billion galaxies like
Euclid will allow constraints on dark energy models.

Simple building blocks of complex biological systems Prof. Uri Alon, Physics of Complex Systems, Weizmann Institute
Prof. Uri Alon, Physics of Complex Systems, Weizmann Institute


To understand biological systems, our lab has defined "network motifs": basic interaction patterns that recur throughout biological networks, much more often than expected at random. The same small set of network motifs appears to serve as the building blocks of the circuitry that processes information from bacteria to mammals. Specific network motifs may be universal building blocks of biological computation. We experimentally studied the function of each network motif in the bacterium E. coli using dynamic fluorescent measurements from living cells. Each network motif can serve as an elementary circuit with a defined function: filters, pulse generators, response accelerators, temporal-pattern generators and more. Evolution seems to have rediscovered the same motifs again and again, perhaps because they are the simplest and most robust circuits that perform these information-processing functions.
Geometry, light and a wee bit of magic Professor Ulf Leonhardt, Weizmann Institute
Professor Ulf Leonhardt, Weizmann Institute


Many mass-produced everyday products of modern technology would appear to be completely magical to our ancestors: mobile phones, television, computers, electric light, cars, etc. Some devices that are still perceived as magical or mysterious are about to appear in the laboratory and are not so mysterious after all. For example, the first prototype of an electromagnetic cloaking device has been made at Duke university in 2006. This device makes an object invisible to microwave radiation of a single frequency and polarization. Cloaking devices may also be turned into their exact opposite: perfect lenses that can focus electromagnetic waves with unlimited precision. At Harvard University, first vital steps towards levitating objects on the forces of the quantum vacuum have been made. At St Andrews, we observed first indications of artificial black holes in the laboratory, using extremely short light pulses in photonic-crystal fibres. Invisibility devices, quantum forces and optical black holes have two things in common: they represent applications of Einstein's general relativity in Maxwell's electromagnetism and their practical demonstrations are made possible by modern metamaterials. I will try to elucidate the scientific principles acting behind the scenes of such "pure and applied magic".

Interpretations of response fluctuations: neurons, networks and simple behavior Professor Shimon Marom, Department of Physiology and Faculty of Electrical Engineering, Technion
Professor Shimon Marom, Department of Physiology and Faculty of Electrical Engineering, Technion


Trial-by-trial response variation is ubiquitous in practically every observable neural scale. I will describe our experimental efforts to measure and interpret these fluctuations over a wide range of timescales in single neurons and large-scale networks, as well as in simple behavioral (psychpohysical) settings. While the statistical nature of the fluctuations is comparable in these different levels of organization, it is difficult - maybe impossible, maybe even meaningless - to attempt accounting for macroscopic fluctuations in terms of microscopic dynamics. Alternative interpretations are offered and experimentally demonstrated.
- Dynamics and mechanics of moving cells Prof. Kinneret Keren, Dept. of Physics, Technion
Prof. Kinneret Keren, Dept. of Physics, Technion


Cell movement is driven by a spatially extended, self-organized, mechanochemical machine consisting of numerous actin polymers, accessory proteins and molecular motors. This impressive assembly self-organizes over several orders of magnitude in space and time, from the fast dynamics of individual molecular-sized building blocks to the persistent motion of whole cells over minutes and hours. We focus on the mechanisms underlying this remarkable self-organization using the simplest available model systems. We combine quantitative analysis of cell morphology and spatio-temporal dynamics at the molecular level with biophysical measurements, toward the goal of understanding how global cell shape and movement are determined. Our results feed into and direct the development of quantitative theoretical models of moving cells. 
Spin injection, propagation and detection in lateral Spintronics devices Dr. Amos Sharoni, Dept. of Physics, Bar-Ilan University
Dr. Amos Sharoni, Dept. of Physics, Bar-Ilan University

Spintronics; composed from spins, electrons and electronics; deals with systems which take advantage of both the spin and charge of the electron. Spintronics based devices are promising candidates for novel electronics, but also exhibit intriguing physical phenomena. I will (partially) review advances in this field, and focus on lateral spin valves. These are useful ferromagnetic/non-magnetic devices that can decouple a pure spin current from an electrical current by using a non-local geometry. We have used lateral spin valves to study spin injection, propagation and detection in metallic devices, as function of material choice and geometry.  

Anderson Localization of Light and Beyond Prof. Mordechai Segev, Faculty of Physics, Technion
Prof. Mordechai Segev, Faculty of Physics, Technion

Anderson Localization is one of the most basic concepts in solid-state physics.
However, experiments on Anderson localization in electronic systems have eluded
scientists for many decades. Several decades after Anderson's prediction, the
concept has been extended to optics, and in 2007 our group has made the first
demonstration of Anderson localization in its original context, where random
fluctuations superimposed upon a periodic structure bring transport to a halt.
Many experimental works have followed in optics and matter-waves. But can
disorder work to increase transport beyond diffusion, and perhaps even beyond
ballistic transport? The talk will review the recent progress on Anderson
localization of light, and will describe experiments and theory demonstrating
disordered–enhanced transport in photonic quasicrystals, and hyper-transport of
light in photonic media with evolving disorder: a new regime of transport in
which an arbitrary wavepacket expands at a rate faster than ballistic.

Patterns in thin elastic sheets Prof. Haim Diamant, School of Chemistry, Tel-Aviv University
Prof. Haim Diamant, School of Chemistry, Tel-Aviv University

The old field of thin-sheet elasticity, dating back to Euler, has had a
remarkable revival in recent years. One of the main reasons has been the
inadequacy of traditional perturbative approaches to account for patterns
observed in ultra-thin sheets. We will review the recent developments and
then focus on an exemplary problem -- a fluid-supported sheet under
compression -- which exhibits periodic ("wrinkled") and localized
("folded") patterns. This system is integrable and reveals a new and
unexpected symmetry.

Physics of Hearing Prof. Robijn Bruinsma, Dept. of Physics, UCLA
Prof. Robijn Bruinsma, Dept. of Physics, UCLA

Our exquisite sense of hearing has fascinated physicists for more than
a century. It has been well established that hearing is an active, energy consuming,
non-linear process. Major experimental progress over the last decade now allows detailed
comparison between theory and experiment. The talk will review the application of
dynamical systems theory to active hearing as well as experimental tests.

OXIDE INTERFACES, PERSPECTIVES FOR NEW PHYSICS AND DEVICES Prof. Yoram Dagan, School of Physics and Astronomy, Tel Aviv University
Prof. Yoram Dagan, School of Physics and Astronomy, Tel Aviv University

Transistors, lasers and solar cells all involve interfacial phenomena. However, while in semiconductors as one moves-away from the interface “free electron” physics takes place, in oxides strong correlations can play an important role. Spin, orbital, and lattice degrees of freedom in the constituting materials can manifest themselves in a new and interesting way at the interface between oxides, bringing new physical concepts and functionalities.   

Since the seminal discovery of Ohtomo and Hwang the interface between SrTiO3 and LaAlO3 became a model system for studying oxide interfaces. Despite the two parent compounds being nonmagnetic insulators a two dimensional electron gas is formed at their interface. This electron gas turned out to be superconducting and magnetic. These properties can be easily tuned using gate voltage that changes the carrier concentration.

In this talk I will review recent developments in oxide interfaces in general and in the LaAlO3/SrTiO3 system in particular. I will describe the physical problems and challenges yet to be surmounted and our group’s effort in this field.

Stretched polymers: single-stranded DNA Prof. Fyl Pincus, Departments of Physics and Materials Science, UC Santa Barbara
Prof. Fyl Pincus, Departments of Physics and Materials Science, UC Santa Barbara

Magnetic tweezer studies of the force-elongation of single stranded DNA at various salt concentrations by the Saleh group at UCSB have discovered several distinct scaling regimes.  At relatively high forces, an unusual behavior is observed where L is the end-to-end length and f is the applied force.  I shall review our understanding of these scaling properties with a speculation concerning the logarithmic behavior in analogy to one dimensional ferromagnets.

Long Coherence Times with Trapped Cold Atoms Professor Nir Davidson, Faculty of Physics, Weizmann Institute
Professor Nir Davidson, Faculty of Physics, Weizmann Institute


Since the advent of laser cooling in the 80’s ultra cold neutral atoms have been extensively used for precision spectroscopic measurements, mostly under free falling conditions and low atomic density where the perturbations of trapping forces and atomic collisions are minimal. We review recent developments that exploit high density trapped ensembles of ultra cold atoms for precision spectroscopy and quantum memories. We show that the negative role of atomic collisions in limiting the attainable atomic coherence time can be suppressed and sometimes even inverted into a positive role.

Diffusion of Cold Atoms in an Optical Lattice Professor David Kessler, Department of Physics, BIU
Professor David Kessler, Department of Physics, BIU


We discuss the problem of diffusion of cold atoms in an atomic trap. In the semiclassical limit, this problem is equivalent to independent particles undergoing a weakly biased random walk in momentum space. The tails of the momentum distribution are determined by the 1/p fall-off of the bias, and have a power-law decay. This gives rise to anomalous behavior if the exponent of the power-law is sufficiently small in magnitude. Then, the equilibrium prediction is that the average kinetic energy is infinite, which is clearly unphysical. Instead, the system never reaches equilibrium, and the distribution is cut off at momenta of order sqrt(t), rendering all moments finite, but growing in time. We show how a harmonic oscillator with a randomly varying (positive) stiffness gives rise to the same phenomenon. Returning to the atomic trap, we consider the resulting distribution of the atomic positions, which is a cut-off Levy distribution. Finally, we discuss the comparison to experiment.

- The Discovery of the Higgs Boson  Prof Eilam Gross,  The Weizmann Institute of Science
Prof Eilam Gross,  The Weizmann Institute of Science

On the 4th of July 2012, both  experiments at the LHC, ATLAS and CMS announced the discovery of a new Higgs like particle.
The story of the Higgs discovery will be told by one of the men inside....

Electrostatic Doping of Novel Materials Prof. Allen Goldman, School of Physics and Astronomy, University of Minnesota
Prof. Allen Goldman, School of Physics and Astronomy, University of Minnesota

Field effect transistor configurations have been employed as electrostatic alternatives to chemical doping of novel materials. They provide exquisite control of material properties, which may include magnetism and superconductivity.  The technique can be used to tune the superconductor-to–insulator transition.  A recent innovation has been to replace the gate insulator, which is usually a high-dielectric constant material, with an ionic liquid. Ionic liquids are molten salts at room temperature. When used as a gate dielectric, ionic liquids can facilitate extraordinarily large charge transfers because of the formation of an electronic double layer, which is in effect a capacitor with a nanometer scale gap.  Recent work involving ultrathin YBa2Cu3O7−x(YBCO) films gate using electronic double layer transistor configurations involving ionic liquids as gate dielectrics will be discussed.  In essence the entire phase diagram of the compound can be traversed.  In principle electrostatic gating using ionic liquids may provide an alternative approach to searching for new superconductors as it may serve as a means of systematically doping putative parent compounds. 


* Supported in part by the NSF under grants NSF/DMR-0709584 and 0854752 and performed in collaboration with Xiang Leng, Javier Garcia-Barriocanal, Joseph Kinney and Boyi Yang.

Coupled 'electron interferometers': entanglement, dephasing, and phasing Prof. Moty Heiblum, Braun Center for Submicron Research, Department of Condensed Matter Physics, Weizmann Institute
Prof. Moty Heiblum, Braun Center for Submicron Research, Department of Condensed Matter Physics, Weizmann Institute

Experiments involving entangling of particles (or systems) may lead either to decoherence, or, alternatively, to coherent interference. I will present three examples of mesoscopic systems, which consist of a two-path electronic Mach-Zehnder interferometer (MZI) coupled to:  (a) 1-d current carrying channel, with shot noise; (b) Fabry-Perot interferometer in a form of a quantum dot (QD); and (c) Another MZI, revealing two-particle interference. In (a), 'post selection' measurement (cross-correlation' of current fluctuations), will recover the lost interference due to the dephasing process.


Long-Range correlations in driven, non-equilibrium systems Prof. David Mukamel, Weizmann Institute
Prof. David Mukamel, Weizmann Institute

Systems driven out of thermal equilibrium often reach a steady state which under generic conditions exhibits long-range correlations. As a result these systems sometimes share some common features with equilibrium systems with long-range interactions, such as the existence of long range-order and spontaneous symmetry breaking in one dimension, ensemble inequivalence and other properties. Some models of driven systems will be presented, and features resulting from the existence of long-range correlations will be discussed.

Nanoscale Self-Assembly Guided by DNA: Structures, Transformations and Rationally Designed Materials Dr. Oleg Gang, Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA
Dr. Oleg Gang, Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA

      The structural plasticity and tunable interactions provided by DNA chains offer a broad range of possibilities to direct the organization of nanoscale objects into well defined systems, as well as to induce the structural transformations on demand. We have studied the assembly of clusters and extended 2D and 3D array architectures from nanoscale components of multiple types driven by DNA recognition and chain effects. Our work explores how DNA-encoded interactions between inorganic nano-components can guide the formation of well-defined superlattices, how the morphology of self-organized structures can be regulated in-situ, and what molecular factors govern a phase behavior. The role of flexible chains, particle anisotropy, and external stimuli on a structure formation and its transformation will be discussed in details. Our recent progress on the assembly of heterogeneous particle superlattices with switchable, tunable, magnetically and optically active properties will be presented.

      Research is supported by the U.S. DOE Office of Science and Office of Basic Energy Sciences under contract No. DE-AC-02-98CH10886.


Neutrino Oscillations and Short Transit Times Prof. Larry Horowitz, Bar Ilan University
Prof. Larry Horowitz, Bar Ilan University

The Stueckelberg formulation of a manifestly covariant relativistic classical and quantum

mechanics is briefly reviewed and it is shown that in this framework a simple model

exists for which, for systems with flavor oscillations, measured beam transit times can be

shortened. We show that this phenomenon could provide a mechanism for a “pull back”

in measured time during the transit of a beam of neutrinos but for which the speed is

almost everywhere less than light speed. The model is shown to be consistent with the

field equations and the Lorentz force for Glashow-Salam-Weinberg type non-Abelian fields

interacting with the leptons. This result can be considered as a prediction of the outcome

of experiments designed to resolve the presently conflicting evidence for this effect.

The pattern behind vegetation patterns and what does it tell us about desertification Prof. Ehud Meron, The Physics Department, Ben Gurion University
Prof. Ehud Meron, The Physics Department, Ben Gurion University

The significance of vegetation patchiness to ecosystem function is well recognized. During the past decade an increasing number of studies have appeared, reporting on the observations of self-organized patchiness in a variety of terrestrial and marine ecosystems. In parallel, model studies have uncovered small-scale biomass-resource feedbacks that give rise to periodic and disordered patterns at large scales, and thus explain the observations. However, the implications of vegetation pattern formation for various ecological processes, such as biodiversity change, desertification and rehabilitation have hardly been studied. In this talk I will focus on pattern formation aspects of desertification and rehabilitation. Unlike the common view of desertification as an abrupt transition from a productive stable state to a less productive alternative stable state, pattern formation theory suggests the likelihood of gradual transitions involving extended pauses at many intermediate stable states of decreasing productivity. This finding calls for re-examination of currently proposed warning signals of imminent desertification. Pattern formation theory also suggests a novel view of rehabilitation of degraded landscapes – rehabilitation as a spatial resonance problem. Motivated by this application, we studied the impact of 1d periodic spatial forcing on 2d pattern forming systems, revealing instabilities that shed new light on current rehabilitation practices. I will conclude with a few comments on the significance of integrating pattern formation theory into spatial ecology.


Interfacial Complexions & Thermodynamic Transitions at Interfaces Prof. Wayne D. Kaplan, Department of Materials Engineering, Technion
Prof. Wayne D. Kaplan, Department of Materials Engineering, Technion

Since the 1980s it has been recognized that the structure of grain boundaries in polycrystalline ceramics can have a diffuse nature, characterized by a ~1nm thick nominally amorphous film.  More recently, the structure of grain boundaries has been described following diffuse interface theory, stating that the structure and chemistry of grain boundaries, interfaces and surfaces can go through two dimensional transitions between thermodynamic states (termed complexions) in order to lower the interface energy.  As such complexions for interfaces are analogous to phases in bulk, although they are not bulk phases.  In the past these conclusions have been reached based on structural characterization of grain boundaries and interfaces correlated with mechanical and electrical properties, and more recently it has been shown that specific complexions can have a significant influence on grain boundary mobility, and thus the morphology of an evolving microstructure.


To date, almost all of these studies have been conducted at grain boundaries in single phase polycrystalline systems, which by definition are not at equilibrium, and in some cases it is not even clear if the identified complexions are at steady-state.  Similar questions have been raised for studies focusing on metal-ceramic interfaces from thin film studies, where the deposition process used to form the samples may be very far from equilibrium. 


This presentation will focus on an experimental approach to address the structure, chemistry and energy of complexions at metal-ceramic interfaces which are fully equilibrated, from which it can be demonstrated that a change in complexion reduces interface energy.  This will be compared with complexions at solid-liquid interfaces, where a region of ordered liquid exists adjacent to the interface at equilibrium, and the details of a reconstructed solid-solid interface where the reconstructed interface structure accommodates lattice mismatch for a nominally incoherent interface.  These three systems will be compared to known reconstructed solid surfaces, which can also be described as complexions, within a more generalized Gibbs adsorption isotherm.




Prof. Yariv Kafri, Technion

The talk will consider energy fluctuations of systems in three different settings (i) An isolated systems who's energy is changed by performing non-adiabatic work using a cyclic process (ii) Two systems which are brought in contact and are approaching thermal equilibrium (iii) A driven dissipative system which is driven by non-adiabatic work and coupled to a large bath. Expressions for the size of energy fluctuations as a function of time in all settings will be derived, assuming that the process is composed of many small steps of energy exchange. In all cases the results depend only on average energy flows in the system and densities of states, independent of any other microscopic detail. In the steady-state an expression relating three key properties: the relaxation time of the system, the energy injection rate, and the size of the fluctuations will be presented.

The Proton Radius - Nuclear Physics' Newest Puzzle Rof. Guy Ron, Racah Institute of Physics, Hebrew University of Jerusalem
Rof. Guy Ron, Racah Institute of Physics, Hebrew University of Jerusalem

The radius of the proton, generally assumed to be a well measured and understood quantity has recently come under scrutiny due to highly precise, yet conflicting, experimental results. These new results have generated a host of interpretations, none of which are completely satisfactory. I will present a general overview to the topic, from the early measurements of the 1950s to the high precision experiments performed today. I will further discuss the various radii and measurements and present some of the attempted explanations for the discrepancies observed.



Prof. Guy Deutscher , Tel Aviv University

Research on Superconductivity at the nano-scale started well before the term "nano" became fashionable. In early contributions dark field microscopy was used and allowed for the first to measure grain sizes and grain size distributions down to the nano-scale in films of granular Aluminum that comprised many layers of grains. Recently research on granular superconductivity is receiving increased attention because of its enhancement in the vicinity to a metal-insulator transition, predicted high temperature superconductivity in small clusters and a possible competition with magnetism. These new developments will be reviewed.

Last Chance for Supersymmetry: Supersymmetry, Dark Matter and the LHC Prof. Yael Shadmi, The Technion
Prof. Yael Shadmi, The Technion

Abstract: Supersymmetry is a beautiful theoretical concept. Its possible relation to the electroweak-breaking scale has fascinated physicists for decades: it may stabilize the Higgs mass, and it predicts Dark Matter candidate(s) near this scale. These days, it is being searched for at the Large Hadron Collider (LHC) at CERN. In this colloquium, I will outline the theoretically compelling features of supersymmetry and discuss the current state of LHC searches for it.

- Baruch Barzel Baruch Barzel (BIU)
Baruch Barzel (BIU)