Scissors mode and superfluidity of a trapped Bose-Einstein condensed gas

TL;DR

This paper studies the scissors mode oscillations in trapped Bose-Einstein condensates to reveal superfluidity effects, comparing with classical gases and discussing experimental excitation methods.

Contribution

It provides a detailed analysis of scissors mode oscillations as a signature of superfluidity in Bose-Einstein condensates, including classical gas comparisons and excitation techniques.

Findings

Superfluid BECs exhibit low-frequency scissors mode components.

Classical gases show different oscillation characteristics above T_c.

Experimental procedures for exciting the scissors mode are analyzed.

Abstract

We investigate the oscillation of a dilute atomic gas generated by a sudden rotation of the confining trap (scissors mode). This oscillation reveals the effects of superfluidity exhibited by a Bose-Einstein condensate. The scissors mode is investigated also in a classical gas above T_c in various collisional regimes. The crucial difference with respect to the superfluid case arises from the occurence of low frequency components, which are responsible for the rigid value of the moment of inertia. Different experimental procedures to excite the scissors mode are discussed.