Rotation of an atomic Bose-Einstein condensate with and without a quantized vortex

TL;DR

This paper theoretically investigates how an atomic Bose-Einstein condensate behaves under rotation in an elliptical trap, analyzing the effects of initial vortices and different methods of inducing rotation.

Contribution

It introduces a comprehensive simulation study of condensate rotation with and without vortices, revealing how initial vortices influence stability and vortex lattice formation.

Findings

Vortices shift instability points to different rotation frequencies.

The method of inducing rotation affects the stability thresholds.

Presence of a vortex alters the condensate's response to rotation.

Abstract

We theoretically examine the rotation of an atomic Bose-Einstein condensate in an elliptical trap, both in the absence and presence of a quantized vortex. Two methods of introducing the rotating potential are considered - adiabatically increasing the rotation frequency at fixed ellipticity, and adiabatically increasing the trap ellipticity at fixed rotation frequency. Extensive simulations of the Gross-Pitaevskii equation are employed to map out the points where the condensate becomes unstable and ultimately forms a vortex lattice. We highlight the key features of having a quantized vortex in the initial condensate. In particular, we find that the presence of the vortex causes the instabilities to shift to lower or higher rotation frequencies, depending on the direction of the vortex relative to the trap rotation.