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

TL;DR

This paper uses TEBD simulations to explore the quantum phase diagram of imbalanced fermion mixtures in one-dimensional optical lattices, revealing conditions for FFLO phases and effects of mass imbalance.

Contribution

It introduces a comprehensive numerical study of the asymmetric Hubbard model with mass imbalance, highlighting the conditions for FFLO phase stability.

Findings

FFLO phase signatures are identified in the model.

Mass imbalance reduces or eliminates the FFLO phase.

The phase diagram depends on interaction strength and mass imbalance.

Abstract

With a recently developed time evolving block decimation (TEBD) algorithm, we numerically study the ground state quantum phase diagram of fermi mixtures with attractive inter-species interactions loaded in one-dimensional optical lattices. For our study, we adopt a general asymmetric Hubbard model (AHM) 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.