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arXiv · 1308.0750

Topological phase transitions driven by non-Abelian gauge potentials in optical square lattices

M. Burrello·I. C. Fulga·E. Alba·L. Lepori·A. Trombettoni
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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.

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M. Burrello, I. C. Fulga, E. Alba, L. Lepori, A. Trombettoni. 2013-11-18. Topological phase transitions driven by non-Abelian gauge potentials in optical square lattices. https://doi.org/10.1103/physreva.88.053619

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