Size and dynamics of vortex dipoles in dilute Bose-Einstein condensates

TL;DR

This paper uses simulations of the Gross-Pitaevskii equation to analyze vortex dipoles in Bose-Einstein condensates, confirming experimental observations and assessing the impact of imaging techniques on vortex dynamics.

Contribution

It provides a quantitative match to experimental vortex dipole sizes and evaluates how imaging methods influence vortex behavior in condensates.

Findings

Simulations agree with experimental vortex dipole sizes.

Imaging induces isotropic size oscillations without disturbing vortex trajectories.

Imaging techniques are effective for real-time superfluid studies.

Abstract

Recently, Freilich et al. [Science 329, 1182 (2010)] experimentally discovered stationary states of vortex dipoles, pairs of vortices of opposite circulation, in dilute Bose-Einstein condensates. To explain their observations, we perform simulations based on the Gross-Pitaevskii equation and obtain excellent quantitative agreement on the size of the stationary dipole. We also investigate how their imaging method, in which atoms are repeatedly extracted from a single condensate, affects the vortex dynamics. We find that it mainly induces isotropic size oscillations of the condensate without otherwise disturbing the vortex trajectories. Thus, the imaging technique appears to be a promising tool for studying real-time superfluid dynamics.