title: Extended hubbard model with ring exchange: a route to a non-Abelian topological phase.
abstract: We propose an extended Hubbard model on a 2D kagome lattice with an additional ring exchange term. The particles can be either bosons or spinless fermions. We analyze the model at the special filling fraction 1/6, where it is closely related to the quantum dimer model. We show how to arrive at an exactly soluble point whose ground state is the "d-isotopy" transition point into a stable phase with a certain type of non-Abelian topological order. Near the "special" values, d=2cos(pi/(k+2), this topological phase has anyonic excitations closely related to SU(2) Chern-Simons theory at level k.
authors.affiliation: Microsoft Research, One Microsoft Way, Redmond, Washington 98052, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Freedman
authors.forename: Chetan
authors.initials: C
authors.lastname: Nayak
authors.forename: Kirill
authors.initials: K
authors.lastname: Shtengel