Lifetime of angular momentum in a rotating strongly interacting Fermi gas

TL;DR

This paper studies how long angular momentum persists in a rotating ultracold Fermi gas under various conditions, revealing long lifetimes near Feshbach resonance due to hydrodynamic effects.

Contribution

It provides experimental insights into the lifetime of angular momentum in strongly interacting Fermi gases and compares results with theoretical models for Boltzmann gases.

Findings

Long angular momentum lifetime near Feshbach resonance

Decay rate depends on trap ellipticity and interaction strength

Results align with Boltzmann gas theory expectations

Abstract

We investigate the lifetime of angular momentum in an ultracold strongly interacting Fermi gas, confined in a trap with controllable ellipticity. To determine the angular momentum we measure the precession of the radial quadrupole mode. We find that in the vicinity of a Feshbach resonance the deeply hydrodynamic behavior in the normal phase leads to a very long lifetime of the angular momentum. Furthermore, we examine the dependence of the decay rate of the angular momentum on the ellipticity of the trapping potential and the interaction strength. The results are in general agreement with the theoretically expected behavior for a Boltzmann gas.