Monday's seminar

[CM]

CONDENSED MATTER AND  STATISTICAL PHYSICS SECTION

   
INFORMAL SEMINAR





Monday, 20 April   -    11:00 a.m.


Seminar Room -  Leonardo Bldg. - first floor






Victor KAGALOVSKY   (Sami Shamoon College of Engg., Beer-Sheva)




"Spin quantum Hall effect in  class C superconductors and  quantum spin 
Hall effect in graphene"


Abstract

We study a delocalization transition in a system of noninteracting 
quasiparticles moving in two dimensions, which belongs to a new symmetry 
class C.  This symmetry class can be realized in a dirty, gapless 
superconductor in which time-reversal symmetry for orbital motion is 
broken, but spin-rotation symmetry is intact. In this class spin current 
is transferred by electron-hole pairs.  Further, we consider a 
three-dimensional realization of class C. In the last part of the talk, 
we discuss application of the generalized Chalker-Coddington network 
model to the quantum spin Hall effect in graphene, which differs 
significantly from class C.  In particular, spin current is transferred 
by electrons with opposite spins moving in the opposite directions.