Destroying superfluidity by rotating a Fermi gas at unitarity

TL;DR

This paper investigates how rotation affects a trapped Fermi gas at unitarity, revealing phase separation between superfluid and normal phases and analyzing stability and deformation under rotation.

Contribution

It demonstrates that rotation induces phase separation in a Fermi gas at unitarity without vortex formation, and characterizes the interface and stability conditions.

Findings

Rotation causes phase separation into superfluid and normal regions.

Density discontinuity at the interface is 0.85, independent of angular velocity.

Critical angular velocity for interface deformation is identified.

Abstract

We study the effect of the rotation on a harmonically trapped Fermi gas at zero temperature under the assumption that vortices are not formed. We show that at unitarity the rotation produces a phase separation between a non rotating superfluid (S) core and a rigidly rotating normal (N) gas. The interface between the two phases is characterized by a density discontinuity $n_{\rm N}/n_{\rm S}= 0.85$, independent of the angular velocity. The depletion of the superfluid and the angular momentum of the rotating configuration are calculated as a function of the angular velocity. The conditions of stability are also discussed and the critical angular velocity for the onset of a spontaneous quadrupole deformation of the interface is evaluated.