Dissipationless flow and superfluidity in gaseous Bose-Einstein condensates

TL;DR

This paper investigates how a moving laser beam causes dissipation in a Bose-Einstein condensate, comparing superfluid and normal gas behaviors to understand superfluidity and dissipation mechanisms.

Contribution

It provides experimental insights into dissipation processes in Bose-Einstein condensates by measuring heating rates induced by a moving laser across the transition temperature.

Findings

Superfluid gas exhibits lower heating rates than normal gas.

Dissipation depends on the velocity of the laser beam.

Results support the understanding of superfluidity in dilute Bose gases.

Abstract

We study dissipation in a dilute Bose gas induced by the motion of a macroscopic object. A blue-detuned laser beam focused on the center of a trapped gas of sodium atoms was scanned both above and below the BEC transition temperature. The measurements allow for a comparison between the heating rates for the superfluid and normal gas.