Massive superfluid vortices and vortex necklaces on a planar annulus

TL;DR

This paper investigates the dynamics of massive superfluid vortices in a planar annulus, revealing oscillatory behaviors, stability thresholds, and the formation of vortex necklaces, supported by analytical models and numerical simulations.

Contribution

It introduces a novel analytical point-vortex model for massive vortices, extending plasma orbit theory, and confirms findings with Gross-Pitaevskii simulations.

Findings

Massive vortices exhibit radial oscillations and become unstable beyond a critical mass.

Vortices tend to move towards the edges of the annulus when unstable.

A vortex necklace configuration is analyzed and characterized.

Abstract

We study a superfluid in a planar annulus hosting vortices with massive cores. An analytical point-vortex model shows that the massive vortices may perform radial oscillations on top of the usual uniform precession of their massless counterpart. Beyond a critical vortex mass, this oscillatory motion becomes unstable and the vortices are driven towards one of the edges. The analogy with the motion of a charged particle in a static electromagnetic field leads to the development of a plasma orbit theory that provides a description of the trajectories which remains accurate even beyond the regime of small radial oscillations. These results are confirmed by the numerical solution of coupled two-component Gross-Pitaevskii equations. The analysis is then extended to a necklace of vortices symmetrically arranged within the annulus.