Chandrasekhar-Clogston limit and phase separation in Fermi mixtures at Unitarity

TL;DR

This paper investigates the phase diagram of a population-imbalanced, mass-imbalanced unitary Fermi gas at zero temperature, identifying phase boundaries and effects of asymmetry on critical polarization using many-body calculations.

Contribution

It provides a detailed analysis of the phase diagram and coexistence conditions, highlighting the impact of mass imbalance on the Chandrasekhar-Clogston limit and phase separation.

Findings

Identification of superfluid, partially polarized, and fully polarized regions.

Explicit discussion of mass imbalance effects on critical polarization.

Prediction of phase-separated configurations in traps.

Abstract

Using many-body results available from diagrammatic and {\it ab initio} Monte Carlo calculations we analyze the phase diagram $\mu=(\mu_{\uparrow}+\mu_{\downarrow})/2$ versus $h=(\mu_{\uparrow}-\mu_{\downarrow})/2$ of a unitary Fermi gas at zero temperature with population imbalance and unequal masses. We identify different regions where the gas is superfluid, partially polarized or fully polarized and determine the corresponding coexistence conditions. The asymmetry in the phase diagram, caused by the mass imbalance, and its effect on the Chandrasekhar-Clogston limit for the critical polarization are explicitly discussed. The equation of state of the superfluid and normal phases is employed, within the local density approximation, to predict novel phase separated configurations in the presence of harmonic trapping potentials.