Enhancement of the scissors mode of an expanding Bose-Einstein condensate

TL;DR

This paper investigates how the scissors mode oscillations of a Bose-Einstein condensate evolve during free expansion, revealing an enhancement of oscillation amplitude after asymptotic expansion.

Contribution

It demonstrates that the sinusoidal scissors mode behavior is recovered with increased amplitude after expansion, providing new insights into superfluid dynamics during ballistic expansion.

Findings

Sinusoidal oscillations are recovered after expansion.

Amplitude of oscillations is enhanced post-expansion.

The shape of the trapping potential influences mode excitation.

Abstract

We study the time-evolution of the scissors mode of a Bose-Einstein condensate during the ballistic expansion after release from the magnetic trap. We show that despite the nontrivial character of the superfluid expansion, the sinusoidal behavior of the scissor oscillations is recovered after an asymptotic expansion, with an enhancement of the final amplitude. We investigate this phenomenon with a condensate held in an elongated magnetostatic potential, whose particular shape allows for the excitation of the scissors mode.