Controlled vortex-sound interactions in atomic Bose-Einstein condensates

The low temperature dynamics of a vortex in a trapped quasi-two-dimensional Bose-Einstein condensate are studied quantitatively. Precession of an off-centred vortex in a dimple trap, embedded in a weaker harmonic trap, leads to the emission of sound in a dipolar radiation pattern. Sound emission and reabsorption can be controlled by varying the depth of the dimple. In a shallow dimple, the power emitted is proportional to the vortex acceleration squared over the precession frequency, whereas for a deep dimple, periodic sound reabsorption stabilises the vortex against radiation-induced decay.