Splitting of a doubly quantized vortex through intertwining in Bose-Einstein condensates

TL;DR

This paper investigates the instability and decay process of doubly quantized vortices in Bose-Einstein condensates, revealing their spectral instability and the intertwining behavior of resulting singly quantized vortices through numerical simulations.

Contribution

It provides a detailed analysis of vortex splitting in BECs, combining spectral stability analysis with 3D simulations, and offers an interpretation of recent experimental observations.

Findings

Doubly quantized vortices are spectrally unstable to splitting.

The split vortices intertwine before decay.

Numerical simulations match experimental results.

Abstract

The stability of doubly quantized vortices in dilute Bose-Einstein condensates of 23Na is examined at zero temperature. The eigenmode spectrum of the Bogoliubov equations for a harmonically trapped cigar-shaped condensate is computed and it is found that the doubly quantized vortex is spectrally unstable towards dissection into two singly quantized vortices. By numerically solving the full three-dimensional time-dependent Gross-Pitaevskii equation, it is found that the two singly quantized vortices intertwine before decaying. This work provides an interpretation of recent experiments [A. E. Leanhardt et al. Phys. Rev. Lett. 89, 190403 (2002)].