Date:2012-09-28, 2:00pm

Venue:Conference Hall 322, Science Building

Title:Recent Progress in Exactly Solvable Discrete Models for Topological Phases in Two Dimensions

Speaker:Prof. Yong-Shi Wu

Department of Phyiscs, Fudan University and

Department of Physics and Astronomy, University of Utah

Abstract:The study of two-dimensional topological phases in condensed mattersystems is a frontier in the field of condensed matter theory as well as topological quantum computation. Discrete or lattice models, which are exactly solvable have been proposed by Kitaev and by Levin and Wen, respectively, some years ago.

Here we present some recent progress in studying these models. The topics to be covered include 1) Duality between the Kitaev and Levin-Wen models in certain special cases; 2) Proof of the topological invariance for these discrete models defined on fluctuating graphs. 3) The computation of ground state degeneracy in the models on a topologically non-trivial surface; 4) Emergent exchange (braiding) and exclusion statistics for quasi-particle excitations (e.g. the so-called fluxons).

Our approach, though closely related to topological field theory and tensor category theory, could be understood by physicists.