Pair-Breaking in Rotating Fermi Gases

TL;DR

This paper investigates how rotation affects pair-breaking in a cold Fermi gas across the BCS-BEC crossover, revealing three distinct regions with different superfluid and normal fluid behaviors.

Contribution

It introduces a detailed analysis of the spatially varying pair-breaking effect in rotating Fermi gases within the BCS framework, highlighting the existence of three distinct regions.

Findings

Identification of three regions: superfluid, mixed, and normal fluid.

No discontinuities in density and current due to region B.

Progressive pair-breaking with increasing distance from the rotation axis.

Abstract

We study the pair-breaking effect of rotation on a cold Fermi gas in the BCS-BEC crossover region. In the framework of BCS theory, which is supposed to be qualitatively correct at zero temperature, we find that in a trap rotating around a symmetry axis, three regions have to be distinguished: (A) a region near the rotational axis where the superfluid stays at rest and where no pairs are broken, (B) a region where the pairs are progressively broken with increasing distance from the rotational axis, resulting in an increasing rotational current, and (C) a normal-fluid region where all pairs are broken and which rotates like a rigid body. Due to region B, density and current do not exhibit any discontinuities.