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 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.
| Original language | English |
|---|---|
| Journal | Physical Review A |
| Volume | 88 |
| Issue number | 5 |
| Pages (from-to) | 53619 |
| ISSN | 2469-9926 |
| DOIs | |
| Publication status | Published - 15 Nov 2013 |
| Externally published | Yes |
Keywords
- Degenerate Fermi gases
- Quantum phase transitions
- Phases: geometric
- dynamic or topological