Floquet Topological Insulator in Graphene

Speaker
Herb A. Fertig, Indiana University, Bloomington
Date
17/01/2013 - 15:30 - 14:00Add to Calendar 2013-01-17 14:00:00 2013-01-17 15:30:00 Floquet Topological Insulator in Graphene   Graphene supports a number of remarkable electronic properties, some of which make it a candidate for certain microelectronic applications.    The challenge, however, of opening a gap in its electronic spectrum has limited its use for basic circuit elements such as transistors.  In this talk I will review recent work in which an analog of such a gapped spectrum is induced by a time-dependent potential. The resulting system turns out to have electronic structure with non-trivial topology, and is an example of a "Floquet Topological Insulator." It supports surprising fundamental behaviors -- including a quantized Hall effect with no magnetic field -- but there are fundamental challenges to predicting its electronic behavior in settings where it can be measured.   I will present results of numerical calculations in which we meet some of these challenges, and show what should be found in the simplest possible measurement geometry, a two-terminal conductor.  I will discuss the features of the results that demonstrate the unusual topology of the electronic structure, as well as surprising properties that are unique to the time-dependent nature of the system.     Resnick (Bld 209), seminar room 201 המחלקה לפיזיקה physics.dept@mail.biu.ac.il Asia/Jerusalem public
Place
Resnick (Bld 209), seminar room 201
Abstract

 

Graphene supports a number of remarkable electronic properties, some
of which make it a candidate for certain microelectronic applications.   
The challenge, however, of opening a gap in its electronic spectrum has limited its use for basic
circuit elements such as transistors.  In this talk I will review recent work
in which an analog of such a gapped spectrum is induced by a time-dependent potential.
The resulting system turns out to have electronic structure with non-trivial
topology, and is an example of a "Floquet Topological Insulator." It supports
surprising fundamental behaviors -- including a quantized Hall effect with
no magnetic field -- but there are fundamental challenges to predicting its
electronic behavior in settings where it can be measured.   I will present
results of numerical calculations in which we meet some of these challenges, and
show what should be found in the simplest possible measurement geometry, a
two-terminal conductor.  I will discuss the features of the results that demonstrate
the unusual topology of the electronic structure, as well as surprising properties
that are unique to the time-dependent nature of the system.

 
 

תאריך עדכון אחרון : 20/11/2012