Vortex rings and vortex ring solitons in shaken Bose-Einstein condensate

TL;DR

This paper investigates vortex rings and vortex ring solitons in shaken Bose-Einstein condensates, analyzing their formation, properties, and energy requirements through theoretical and numerical methods.

Contribution

It introduces a description of vortex ring solitons as nonlinear Hermite-Laguerre modes using optimized perturbation theory and compares their energy thresholds with vortex rings.

Findings

Vortex rings form at lower energy than vortex ring solitons.

Vortex ring solitons are characterized as nonlinear Hermite-Laguerre modes.

Numerical simulations demonstrate vortex ring generation in trapped $^{87}$Rb atoms.

Abstract

In a shaken Bose-Einstein condensate, confined in a vibrating trap, there can appear different nonlinear coherent modes. Here we concentrate on two types of such coherent modes, vortex ring solitons and vortex rings. In a cylindrical trap, vortex ring solitons can be characterized as nonlinear Hermite-Laguerre modes, whose description can be done by means of optimized perturbation theory. The energy, required for creating vortex ring solitons, is larger than that needed for forming vortex rings. This is why, at a moderate excitation energy, vortex rings appear before vortex ring solitons. The generation of vortex rings is illustrated by numerical simulations for trapped $^{87}$Rb atoms.