Dynamics of a single vortex line in a condensate

TL;DR

This paper experimentally investigates the behavior of a single vortex line in a rotating Bose-Einstein condensate, analyzing its shape, oscillations, and angular momentum to understand vortex dynamics.

Contribution

It provides experimental measurements of vortex line curvature, quadrupole oscillations, and develops a theoretical model linking these to angular momentum in a condensate.

Findings

Vortex lines are mostly curved at the ends as predicted.

Measurements of quadrupole oscillations reveal vortex influence.

Angular momentum per particle correlates with vortex line shape.

Abstract

We study experimentally the line of a single vortex in a rotating prolate Bose-Einstein condensate confined in a harmonic potential. In agreement with predictions, we find that the vortex line is in most cases curved at the ends. We also present measurements of the quadrupole oscillation of the condensate in presence of a single vortex. A theoretical treatment to account for the short time and long time behaviors of these modes is developed. Finally, we use these measurements to infer the angular momentum per particle and relate it to the shape of the vortex line.