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

TY - JOUR

T1 - Topological phase transitions driven by non-Abelian gauge potentials in optical square lattices

AU - Burrello, M.

AU - Fulga, I. C.

AU - Alba, E.

AU - Lepori, L.

AU - Trombettoni, A.

PY - 2013/11/15

Y1 - 2013/11/15

N2 - 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 nontrivial 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.

AB - 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 nontrivial 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.

KW - Degenerate Fermi gases

KW - Quantum phase transitions

KW - Phases: geometric

KW - dynamic or topological

U2 - 10.1103/PhysRevA.88.053619

DO - 10.1103/PhysRevA.88.053619

M3 - Journal article

SN - 2469-9926

VL - 88

SP - 53619

JO - Physical Review A - Atomic, Molecular, and Optical Physics

JF - Physical Review A - Atomic, Molecular, and Optical Physics

IS - 5

ER -