Nonlinear quantum piston for the controlled generation of vortex rings and soliton trains

TL;DR

This paper introduces a quantum piston method to controllably generate vortex rings and soliton trains in Bose-Einstein condensates, exploring their properties and interactions in multi-component superfluids.

Contribution

It presents a novel quantum piston scheme for creating and studying nonlinear excitations like vortex rings and solitons in BECs, including multi-component interactions and skyrmion formation.

Findings

Vortex rings form via transverse instability of shock waves.

Interactions within the condensate influence excitation properties.

Skyrmions emerge in two-component immiscible BECs.

Abstract

We propose a simple way to generate nonlinear excitations in a controllable way by managing interactions in Bose-Einstein condensates. Under the action of a quantum analogue of a classical piston the condensed atoms are pushed through the trap generating vortex rings in a fully three- dimensional condensates or soliton trains in quasi-one dimensional scenarios. The vortex rings form due to transverse instability of the shock wave train enhanced and supported by the energy transfer between waves. We elucidate in which sense the self-interactions within the atom cloud define the properties of generated vortex rings and soliton trains. Based on the quantum piston scheme we study the behavior of two component Bose-Einstein condensates and analyze how the presence of an additional superfluid influences the generation of vortex rings or solitons in the other component and vice versa. Finally, we show the dynamical emergence of skyrmions within two component systems in the immiscible regime.