Crow instability in unitary Fermi gas

TL;DR

This paper studies how Crow instability causes vortex-antivortex pairs in an inhomogeneous unitary Fermi gas to decay into vortex rings and sound waves, using a zero-temperature non-linear Schrödinger model.

Contribution

It introduces a detailed analysis of Crow instability dynamics in a unitary Fermi gas with inhomogeneity, employing phase-imprinting and obstacle methods.

Findings

Crow instability leads to vortex ring formation.

Vortex pairs decay into sound waves.

Decay process depends on initial vortex generation method.

Abstract

We investigate the initiation and subsequent evolution of Crow instability in an inhomogeneous unitary Fermi gas using zero-temperature Galilei-invariant non-linear Schr\"odinger equation. Considering a cigar-shaped unitary Fermi gas, we generate the vortex-antivortex pair either by phase-imprinting or by moving a Gaussian obstacle potential. We observe that the Crow instability in a unitary Fermi gas leads to the decay of the vortex-antivortex pair into multiple vortex rings and ultimately into sound waves.