Instabilities of wave function monopoles in Bose-Einstein condensates

TL;DR

This paper analyzes the stability of monopole solutions in two-component Bose-Einstein condensates, revealing dynamical instabilities and contrasting hydrodynamic descriptions, with implications for manipulating condensates.

Contribution

It provides analytic and numerical insights into monopole instabilities and compares two hydrodynamic models for two-component condensates, highlighting their different phenomena.

Findings

Dynamical instabilities lead to vortex production.

Two distinct hydrodynamic descriptions exist for the same system.

Potential sharpness influences condensate manipulation.

Abstract

We present analytic and numerical results for a class of monopole solutions to the two-component Gross-Pitaevski equation for a two-species Bose condensate in an effectively two-dimensional trap. We exhibit dynamical instabilities involving vortex production as one species pours through another, from which we conclude that the sub-optical sharpness of potentials exerted by matter waves makes condensates ideal tools for manipulating condensates. We also show that there are two equally valid but drastically different hydrodynamic descriptions of a two-component condensate, and illustrate how different phenomena may appear simpler in each.