Date/Time
Date(s) - 24/09/2008
3:20 pm - 4:20 pm

Title: Fractionalization of charge and statistics in weakly interacting systems

Speaker: Dr. Marcel Franz

Institute: University of British Columbia

Location: ABB 102

Description:

Particles with fractional charge, e.g. e/3, can arise as the collective excitations of certain many-body systems. The canonical example of such fractionalization is a 2-dimensional electron gas placed in a transverse magnetic field. At certain values of the magnetic field strength the many-body ground state becomes a strongly-correlated “Laughlin liquid” whose excitations carry fractional charge and also obey fractional statistics, i.e. are neither fermions nor bosons. A long-standing question in this field has been what are the minimal conditions for the fractionalization to occur: Are strong correlations necessary? Is time-reversal symmetry breaking essential? In this talk I will explain why these issues are fundamentally important and interesting, how they relate, among other things to quantum information processing, and describe some simple models, developed very recently, that demonstrate fractionalization in weakly-correlated, time-reversal invariant systems.