Asymmetric two-component Fermi gas with unequal masses

TL;DR

This paper investigates the phase diagram of an asymmetric two-component Fermi gas at zero temperature, exploring various phases, topological transitions, and collective excitations across different interaction regimes.

Contribution

It provides a comprehensive analysis of the phase diagram considering mass anisotropy and population imbalance, including the derivation of collective excitation spectra.

Findings

Identification of normal and superfluid phases across regimes

Analysis of topological quantum phase transitions

Derivation of collective excitation spectrum in BEC limit

Abstract

We analyze the zero temperature phase diagram for an asymmetric two-component Fermi gas as a function of mass anisotropy and population imbalance. We identify regions corresponding to normal, or uniform/non-uniform superfluid phases, and discuss topological quantum phase transitions in the Bardeen-Cooper-Schrieffer (BCS), unitarity and Bose-Einstein condensation (BEC) limits. Lastly, we derive the zero temperature low frequency and long wavelength collective excitation spectrum, and recover the Bogoliubov relation for weakly interacting dilute bosons in the BEC limit.