Self-similar expansion of the density profile in a turbulent Bose-Einstein condensate

TL;DR

This paper investigates how turbulence and distributed vorticity in a Bose-Einstein condensate affect its free expansion, revealing a self-similar density profile expansion that deviates from typical non-rotating condensates.

Contribution

It provides a qualitative explanation for the anomalous expansion behavior of turbulent Bose-Einstein condensates due to pervasive vorticity.

Findings

The aspect ratio remains unchanged during free expansion in turbulent condensates.

Vorticity distribution influences the expansion dynamics, counteracting typical aspect ratio reversal.

Self-similar expansion of the density profile is observed in turbulent BECs.

Abstract

In a recent study we demonstrated the emergence of turbulence in a trapped Bose-Einstein condensate of Rb-87 atoms. An intriguing observation in such a system is the behavior of the turbulent cloud during free expansion.The aspect ratio of the cloud size does not change in the way one would expect for an ordinary non-rotating (vortex-free) condensate. Here we show that the anomalous expansion can be understood, at least qualitatively, in terms of the presence of vorticity distributed throughout the cloud, effectively counteracting the usual reversal of the aspect ratio seen in free time-of-flight expansion of non-rotating condensates.