Interaction-driven topological phase transition in a p -orbital honeycomb optical lattice

Abstract

We investigate the phase diagram of interacting $p$-orbital Fermi atoms on honeycomb optical lattice. We find that the interatomic interactions play critical roles in such $p$-orbital systems, which can drive a first-order topological transition from normal phases with trivial topology to topological phases with nonvanishing Chern numbers. Due to the interplay among atomic interactions, the sublattice potential, and the filling factors, the phase diagram of the system exhibits rich phases, which are characterized by Chern numbers and corresponding edge states. Furthermore, the evolution of the band structures and the moving of Dirac cones along with the phase transitions are also discussed.