Classical-like wakes past elliptical obstacles in atomic Bose-Einstein condensates

TL;DR

This study numerically explores how elongated obstacles in superfluid flow induce vortex nucleation and classical-like wakes in Bose-Einstein condensates, providing insights into quantum turbulence generation.

Contribution

It demonstrates that elliptical obstacles promote vortex formation and turbulence more effectively than circular ones in superfluid flows.

Findings

Elliptical obstacles enhance vortex nucleation.

Wakes resemble classical viscous flows.

More efficient quantum turbulence generation.

Abstract

We reinvestigate numerically the classic problem of two-dimensional superfluid flow past an obstacle. Taking the obstacle to be elongated (perpendicular to the flow), rather than the usual circular form, is shown to promote the nucleation of quantized vortices, enhance their subsequent interactions, and lead to wakes which bear striking similarity to their classical (viscous) counterparts. Then, focussing on the recent experiment of Kwon et al. (arXiv:1403.4658) in a trapped condensate, we show that an elliptical obstacle leads to a cleaner and more efficient means to generate two-dimensional quantum turbulence.