Suppression of Kelvon-induced decay of quantized vortices in oblate Bose-Einstein Condensates

TL;DR

This study demonstrates that increasing confinement in oblate Bose-Einstein condensates suppresses Kelvin mode excitations, significantly reducing vortex decay rates and highlighting the transition from three-dimensional to two-dimensional vortex dynamics.

Contribution

The paper introduces a method to suppress Kelvin mode excitations in vortices by tightening confinement, revealing the transition to two-dimensional vortex behavior and aligning simulations with experimental results.

Findings

Kelvin mode activation can be suppressed by tighter confinement.

Vortex decay rate decreases with increased oblatness of the trap.

Decay rates are highly sensitive to temperature and dimensionality near the transition.

Abstract

We study the Kelvin mode excitations on a vortex line in a three-dimensional trapped Bose-Einstein condensate at finite temperature. Our stochastic Gross-Pitaevskii simulations show that the activation of these modes can be suppressed by tightening the confinement along the direction of the vortex line, leading to a strong suppression in the vortex decay rate as the system enters a regime of two-dimensional vortex dynamics. As the system approaches the condensation transition temperature we find that the vortex decay rate is strongly sensitive to dimensionality and temperature, observing a large enhancement for quasi-two-dimensional traps. Three-dimensional simulations of the recent vortex dipole decay experiment of Neely et al. [Phys. Rev. Lett. 104, 160401 (2010)] confirm two-dimensional vortex dynamics, and predict a dipole lifetime consistent with experimental observations and suppression of Kelvon-induced vortex decay in highly oblate condensates.