Controllable splitting dynamics of a doubly quantized vortex in a rotating ring-shaped condensate

TL;DR

This paper investigates the formation, stability, and decay of doubly quantized vortices in ring-shaped Bose-Einstein condensates under various trap symmetries, revealing geometry-dependent dynamics and instability thresholds.

Contribution

It provides a detailed analysis of the controllable splitting and decay mechanisms of doubly quantized vortices in ring-shaped condensates with different trap anisotropies.

Findings

DQV can be stably created in symmetric traps.

Small anisotropy causes DQV to split and revive, then decay.

Large anisotropy leads to rapid DQV decay into singly quantized vortices.

Abstract

We study the dynamics of a doubly quantized vortex (DQV), created by releasing a ring-shaped Bose-Einstein condensate with quantized circulation into harmonic potential traps. It is shown that a DQV can be generated and exists stably in the middle of the ring-shaped condensate with the initial circulation $s = 2$ after released into the rotationally symmetric trap potential. For an asymmetric trap with a small degree of anisotropy the DQV initially splits into two singly quantized vortices and revives again but eventually evolves into two unit vortices due to the dynamic instability. For the degree of anisotropy above a critical value, the DQV is extremely unstably and decays rapidly into two singlet vortices. The geometry-dependent lifetime of the DQV and vortex-induced excitations are also discussed intensively.