Collective modes as a probe of the equation of state for partially polarized Fermi gases

TL;DR

This paper investigates how collective oscillation modes in a partially polarized Fermi gas can reveal details about its equation of state across the BCS-BEC crossover, highlighting the breathing mode's diagnostic potential.

Contribution

It demonstrates that the breathing mode frequency varies non-monotonically with polarization and can differentiate between different unitary gas equations of state.

Findings

Breathing mode frequency shows non-monotonic behavior with polarization.

Breathing mode can distinguish between equations of state.

Results apply across the entire BCS-BEC crossover.

Abstract

We calculate the collective modes of a partially polarized Fermi gas trapped in a spherically symmetric harmonic potential. We show that the breathing mode frequency exhibits non-monotonic dependence on polarization in the entire BCS-BEC crossover region. Moreover, we find that the breathing mode can be used to distinguish between two commonly used unitary gas equations of state.