Vortex gyroscope imaging of planar superfluids

TL;DR

The paper introduces a new imaging method using vortex gyroscope imaging to identify vortex signs in 2D superfluids, facilitating studies of vortex dynamics and phase transitions.

Contribution

It presents a novel tilting-based imaging technique to distinguish vortices from antivortices in Bose-Einstein condensates from a single density image.

Findings

Enables experimental detection of vortex signs in superfluids.

Facilitates measurement of the kinetic energy spectrum.

Supports observation of negative temperature phase transition.

Abstract

We propose a robust imaging technique that makes it possible to distinguish vortices from antivortices in quasi-two-dimensional Bose--Einstein condensates from a single image of the density of the atoms. Tilting the planar condensate prior to standard absorption imaging excites a generalized gyroscopic mode of the condensate revealing the sign and location of each vortex. This technique is anticipated to enable experimental measurement of the incompressible kinetic energy spectrum of the condensate and the observation of a negative temperature phase transition of the vortex gas, driven by two-dimensional superfluid turbulence.