Superconductor-insulator transitions: Phase diagram and magnetoresistance
Seminar
Speaker
Igor Burmistrov (Landau Institute for Theoretical Physics, Russia)
Date
19/11/2015 - 15:30 - 14:30Add to Calendar
2015-11-19 14:30:00
2015-11-19 15:30:00
Superconductor-insulator transitions: Phase diagram and magnetoresistance
In this talk I discuss the influence of disorder-induced Anderson localization and of electron-electron interaction on superconductivity in two-dimensional systems. I present the results for the superconducting transition temperature $T_c$, the temperature dependence of the resistivity, the phase diagram, as well as the magnetoresistance. The analysis is based on the renormalization group for the Finkelstein nonlinear sigma model.
Derived RG equations are valid to the lowest order in disorder but for strong enough electron-electron interaction strength in particle-hole and Cooper channels. The analysis is applied to systems with preserved and broken spin-rotational symmetry as well as with short-range and with long-range (Coulomb) interaction. In the cases of short-range interaction, there is a large parameter region where the superconductivity is enhanced by localization effects.
The RG analysis indicates that the superconductor-insulator transition is controlled by a fixed point with a resistivity $R_c$ of the order of the quantum resistance $R_q = h/ 4e^2$. When a transverse magnetic field is applied, we find a strong nonmonotonous magnetoresistance for temperatures
below $T_c$.
The talk is based on the following papers:
[1] I.S. Burmistrov, I.V. Gornyi, A.D. Mirlin, Phys.Rev. B92, 014506 (2015); Phys. Rev. Lett. 108, 017002 (2012)
[2] E.J. Koenig, A. Levchenko, I.V. Protopopov, I.V. Gornyi, I.S. Burmistrov, A.D. Mirlin, arxiv:1509.01474
Resnick Building 209, room 210
המחלקה לפיזיקה
physics.dept@mail.biu.ac.il
Asia/Jerusalem
public
Place
Resnick Building 209, room 210
Abstract
In this talk I discuss the influence of disorder-induced Anderson localization and of electron-electron interaction on superconductivity in two-dimensional systems. I present the results for the superconducting transition temperature $T_c$, the temperature dependence of the resistivity, the phase diagram, as well as the magnetoresistance. The analysis is based on the renormalization group for the Finkelstein nonlinear sigma model.
Derived RG equations are valid to the lowest order in disorder but for strong enough electron-electron interaction strength in particle-hole and Cooper channels. The analysis is applied to systems with preserved and broken spin-rotational symmetry as well as with short-range and with long-range (Coulomb) interaction. In the cases of short-range interaction, there is a large parameter region where the superconductivity is enhanced by localization effects.
The RG analysis indicates that the superconductor-insulator transition is controlled by a fixed point with a resistivity $R_c$ of the order of the quantum resistance $R_q = h/ 4e^2$. When a transverse magnetic field is applied, we find a strong nonmonotonous magnetoresistance for temperatures
below $T_c$.
The talk is based on the following papers:
[1] I.S. Burmistrov, I.V. Gornyi, A.D. Mirlin, Phys.Rev. B92, 014506 (2015); Phys. Rev. Lett. 108, 017002 (2012)
[2] E.J. Koenig, A. Levchenko, I.V. Protopopov, I.V. Gornyi, I.S. Burmistrov, A.D. Mirlin, arxiv:1509.01474
תאריך עדכון אחרון : 07/10/2015
