Topological phase transitions driven by gauge fields in an exactly solvable model

摘要

We demonstrate the existence of a new topologically ordered phase in Kitaev'shoneycomb lattice model. This new phase appears due to the presence of a vortexlattice and it supports chiral Abelian anyons. We characterize the phase by itslow-energy behavior that is described by a distinct number of Dirac fermions.We identify two physically distinct types of topological phase transitions andobtain analytically the critical behavior of the extended phase space. TheFermi surface evolution associated with the transitions is shown to be due tothe Dirac fermions coupling to chiral gauge fields. Finally, we describe howthe new phase can be understood in terms of interactions between the anyonicvortices.