The Snake Instability of Ring Dark Solitons in Toroidally Trapped Bose-Einstein Condensates

TL;DR

This paper investigates the snake instability in ring dark solitons within toroidally trapped Bose-Einstein condensates, linking symmetry breaking and Bogoliubov modes to vortex formation, and showing confinement effects on soliton decay.

Contribution

It explicitly connects imaginary Bogoliubov modes with snake instability and introduces a simple model explaining the instability mechanism in toroidal BECs.

Findings

Snake instability requires broken symmetry.

Imaginary Bogoliubov modes predict vortex pairs.

Tight confinement enhances soliton decay.

Abstract

We show that the onset of the snake instability of ring dark solitons requires a broken symmetry. We also elucidate explicitly the connection between imaginary Bogoliubov modes and the snake instability, predicting the number of vortex-anti-vortex pairs produced. In addition, we propose a simple model to give a physical motivation as to why the snake instability takes place. Finally, we show that tight confinement in a toroidal potential actually enhances soliton decay due to inhibition of soliton motion.