Scissors mode of a rotating Bose-Einstein condensate

TL;DR

This paper investigates the scissors mode in a rotating Bose-Einstein condensate, combining theoretical predictions with experimental measurements to understand symmetry breaking and shape oscillations at high angular velocities.

Contribution

It provides the first combined theoretical and experimental analysis of the scissors mode and shape oscillations in a rotating Bose-Einstein condensate.

Findings

Scissors mode frequency vanishes at high angular velocities.

Experimental measurements confirm theoretical predictions.

Shape oscillations are observed and match calculations.

Abstract

A scissors mode of a rotating Bose-Einstein condensate is investigated both theoretically and experimentally. The condensate is confined in an axi-symmetric harmonic trap, superimposed with a small rotating deformation. For angular velocities larger than $\omega_\perp/\sqrt2 $, where $\omega_\perp$ is the radial trap frequency, the frequency of the scissors mode is predicted to vanish like the square root of the deformation, due to the tendency of the system to exhibit spontaneous rotational symmetry breaking. Measurements of the frequency confirm the predictions of theory. Accompanying characteristic oscillations of the internal shape of the condensate are also calculated and observed experimentally.