Zero temperature damping of Bose-Einstein condensate oscillations by vortex-antivortex pair creation

TL;DR

This paper studies how vortex-antivortex pairs are created in a 2D Bose-Einstein condensate at zero temperature, leading to nonexponential decay of oscillations, and links this to quantum electrodynamics analogies.

Contribution

It introduces the concept of vortex-antivortex pair creation as a dominant damping mechanism in condensate oscillations at zero temperature.

Findings

Decay of oscillations is nonexponential.

Dissipation rate depends strongly on oscillation amplitude.

Experimental observation can confirm the hydrodynamical analogy.

Abstract

We investigate vortex-antivortex pair creation in a supersonically expanding and contracting quasi-2D Bose-Einstein condensate at zero temperature. For sufficiently large amplitude condensate oscillations, pair production provides the leading dissipation mechanism. The condensate oscillations decay in a nonexponential fashion, and the dissipation rate depends strongly on the oscillation amplitude. These features allow to distinguish the decay due to pair creation from other possible damping mechanisms. Experimental observation of the predicted oscillation behavior of the superfluid gas provides a direct confirmation of the hydrodynamical analogy of quantum electrodynamics and quantum vortex dynamics in two spatial dimensions.