Quantum phase diagram of fermion mixtures with population imbalance in one-dimensional optical lattices

Abstract

With a recently developed time-evolving block decimation algorithm, we numerically study the ground-state quantum phase diagram of Fermi mixtures with attractive interspecies interactions loaded in one-dimensional optical lattices. For our study, we adopt a general asymmetric Hubbard model with species-dependent tunneling rates to incorporate the possibility of mass imbalance in the mixtures. We find clear signatures for the existence of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase in this model in the presence of population imbalance. Our simulation also reveals that in the presence of mass imbalance, the parameter space for FFLO states shrinks or even completely vanishes depending on the strength of the attractive interaction and the degree of mass imbalance.