Stability and dynamics of matter-wave vortices in the presence of collisional inhomogeneities and dissipative perturbations

TL;DR

This paper investigates the spectral properties and stability of a vortex in a Bose-Einstein condensate within an anisotropic trap, focusing on how inhomogeneous interactions and dissipation influence vortex dynamics and instabilities.

Contribution

It provides analytical and numerical analysis of the anomalous mode and its role in vortex precession and stability under inhomogeneous and dissipative effects.

Findings

Inhomogeneous interactions induce oscillatory instabilities.

Dissipative perturbations can destabilize the vortex.

Anomalous mode analysis predicts vortex dynamics and instabilities.

Abstract

In this work, the spectral properties of a singly-charged vortex in a In this work, the spectral properties of a singly-charged vortex in a Bose-Einstein condensate confined in a highly anisotropic (disk-shaped) harmonic trap are investigated. Special emphasis is given on the analysis of the so-called anomalous (negative energy) mode of the Bogoliubov spectrum. We use analytical and numerical techniques to illustrate the connection of the anomalous mode to the precession dynamics of the vortex in the trap. Effects due to inhomogeneous interatomic interactions and dissipative perturbations motivated by finite temperature considerations are explored. We find that both of these effects may give rise to oscillatory instabilities of the vortex, which are suitably diagnosed through the perturbation-induced evolution of the anomalous mode, and being monitored by direct numerical simulations.