Coherent cross-talk and parametric driving of matter-wave vortices

TL;DR

This paper demonstrates how sound waves mediate long-range interactions between vortices in Bose-Einstein condensates, enabling energy exchange and control via parametric driving, with observable effects in experiments.

Contribution

It reveals the mechanism of vortex-sound cross-talk in double-well traps and introduces a method to control vortex energy using a precessing obstacle.

Findings

Significant energy transfer between vortices observed in simulations.

Vortex migration to higher density states due to sound interactions.

Controlled energy injection into vortices via parametric driving.

Abstract

We show that the interaction between vortices and sound waves in atomic Bose-Einstein condensates can be elucidated in a double-well trap: with one vortex in each well, the sound emitted by each precessing vortex can be driven into the opposing vortex (if of the same polarity). This cross-talk leads to a periodic exchange of energy between the vortices which is long-range and highly efficient. The increase in vortex energy (obtained by numerical simulations of the Gross-Pitaevskii equation) is significant and experimentally observable as a migration of the vortex to higher density over just a few precession periods. Similar effects can be controllably engineered by introducing a precessing localised obstacle into one well as an artificial generator of sound, thereby demonstrating the parametric driving of energy into a vortex.