Phase diagram of imbalanced strongly interacting fermions on a one-dimensional optical lattice

TL;DR

This paper maps out the phase diagram of imbalanced strongly interacting fermions in a one-dimensional optical lattice, revealing superfluid, insulating, and phase-separated regimes with complex microscopic and macroscopic behaviors.

Contribution

It introduces a phase diagram for the Hubbard model with particle-assisted tunneling, highlighting new phases and phase separation phenomena in imbalanced fermionic systems.

Findings

Identification of superfluid, insulating, and phase-separated regimes.

Microscopic coexistence of phases at balanced populations.

Macroscopic phase segregation above a critical polarization.

Abstract

We show that the Hubbard Hamiltonian with particle-assisted tunneling rates --recently proposed to model a fermionic mixture near a broad Feshbach resonance-- displays a ground state phase diagram with superfluid, insulating, and phase separated regimes. In the latter case, when the populations are balanced the two phases coexist in microscopic antiferromagnetic domains. Macroscopic phase segregation into a high-density superfluid of molecules, and a low-density Fermi liquid of single atoms appears in the density profile above a critical polarization p_c.