English

An extended Hubbard model with ring exchange: a route to a non-Abelian topological phase

Strongly Correlated Electrons 2007-05-23 v2

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 . At a special filling fraction of 1/6 the model is analyzed in the lowest non-vanishing order of perturbation theory. Such ``undoped'' model is closely related to the Quantum Dimer Model. We show how to arrive at an exactly soluble point whose ground state manifold is the extensively degenerate ``d-isotopy space'', a necessary precondition for for a certain type of non-Abelian topological order. Near the ``special'' values, d=2cosπ/(k+2)d = 2 \cos \pi/(k+2), this space is expected to collapse to a stable topological phase with anyonic excitations closely related to SU(2) Chern-Simons theory at level k.

Keywords

Cite

@article{arxiv.cond-mat/0312273,
  title  = {An extended Hubbard model with ring exchange: a route to a non-Abelian topological phase},
  author = {Michael Freedman and Chetan Nayak and Kirill Shtengel},
  journal= {arXiv preprint arXiv:cond-mat/0312273},
  year   = {2007}
}

Comments

4 pages, 2 colour figures, submitted to PRL. For an extended treatment of a more general family of models see cond-mat/0309120