Topological phase transitions driven by non-Abelian gauge potentials in optical square lattices
Abstract
We analyze a tight-binding model of ultracold fermions loaded in an optical square lattice and subjected to a synthetic non-Abelian gauge potential featuring both a magnetic field and a translationally invariant SU(2) term. We consider in particular the effect of broken time-reversal symmetry and its role in driving non-trivial topological phase transitions. By varying the spin-orbit coupling parameters, we find both a semimetal/insulator phase transition and a topological phase transition between insulating phases with different numbers of edge states. The spin is not a conserved quantity of the system and the topological phase transitions can be detected by analyzing its polarization in time of flight images, providing a clear diagnostic for the characterization of the topological phases through the partial entanglement between spin and lattice degrees of freedom.
Keywords
Cite
@article{arxiv.1308.0750,
title = {Topological phase transitions driven by non-Abelian gauge potentials in optical square lattices},
author = {M. Burrello and I. C. Fulga and E. Alba and L. Lepori and A. Trombettoni},
journal= {arXiv preprint arXiv:1308.0750},
year = {2013}
}
Comments
Published version with several extensions and improvements, 13 pages, 10 figures