Evidence for a critical velocity in a Bose-Einstein condensed gas

TL;DR

This paper investigates the dissipation behavior in a Bose-Einstein condensate by moving a laser beam through it, revealing a critical velocity above which significant heating occurs, indicating a threshold for superfluidity.

Contribution

The study provides experimental evidence for a critical velocity in a Bose-Einstein condensate, advancing understanding of superfluid behavior in quantum gases.

Findings

Heating occurs only above a specific critical velocity.

Dissipation is negligible below the critical velocity.

Supports the existence of a superfluid critical velocity in BECs.

Abstract

We have studied dissipation in a Bose--Einstein condensed gas by moving a blue detuned laser beam through the condensate at different velocities. Strong heating was observed only above a critical velocity.