A recent formulation of quantum number fractionalization in 2d via a discrete Z2 gauge theory has pointed to the importance
of ring exchange processes. In particular, for Bosonic models with xy symmetry, ring exchange terms
tend to suppress single strength but not double strength vortices. This tends to enhance the likelihood
of condensing double strength vortices, which is the basic mechanism behind 2d fractionalization.
In this talk I will describe recent preliminary attempts to analyze microscopic ring-exchange models in search of such
2d fractionalization.
Copyright. All Rights Reserved.