Signature of the FFLO phase in the collective modes of a trapped ultracold Fermi gas

TL;DR

This paper theoretically investigates the collective modes of an imbalanced ultracold Fermi gas in a quasi-one-dimensional trap, identifying signatures of the FFLO phase that could be used for experimental detection.

Contribution

It introduces a mean-field approach to identify distinctive collective mode responses indicative of the FFLO phase in trapped Fermi gases.

Findings

Large-scale response signatures are characteristic of the FFLO phase.

Short-wavelength potentials reveal dramatic responses in the collective modes.

The results suggest a new experimental method to detect the FFLO state.

Abstract

We study theoretically the collective modes of a two-component Fermi gas with attractive interactions in a quasi-one-dimensional harmonic trap. We focus on an imbalanced gas in the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase. Using a mean-field theory, we study the response of the ground state to time-dependent potentials. For potentials with short wavelengths, we find dramatic signatures in the large-scale response of the gas which are characteristic of the FFLO phase. This response provides an effective way to detect the FFLO state in experiments.