Dipole Oscillations of a Bose-Einstein Condensate in Presence of Defects and Disorder

TL;DR

This paper investigates how defects and disorder affect dipole oscillations in a Bose-Einstein condensate, revealing the relationship between superfluidity breaking, damping, and nonlinear dissipative flow, with dissipationless flow at high velocities.

Contribution

It demonstrates the connection between superfluidity loss, damping, and nonlinear flow in BECs with defects or disorder, highlighting velocity-dependent dissipation behavior.

Findings

Damping of oscillations linked to nonlinear dissipative flow.

Superfluidity breaks down due to defects and disorder.

Flow becomes dissipationless at supersonic velocities.

Abstract

We consider dipole oscillations of a trapped dilute Bose-Einstein condensate in the presence of a scattering potential consisting either in a localized defect or in an extended disordered potential. In both cases the breaking of superfluidity and the damping of the oscillations are shown to be related to the appearance of a nonlinear dissipative flow. At supersonic velocities the flow becomes asymptotically dissipationless.