Observation of shock waves in a large Bose-Einstein condensate

TL;DR

This paper reports the experimental observation of shock waves in a large Bose-Einstein condensate of sodium atoms, demonstrating wave formation, breaking, and fringe patterns, with theoretical modeling showing excellent agreement.

Contribution

First experimental observation of shock waves in a large BEC using a light barrier, with detailed modeling and analysis of wave breaking phenomena.

Findings

Shock waves form and break in BEC upon barrier interaction

Wave fronts split into fringes near healing length

Model matches experimental results with no significant heating or loss

Abstract

We observe the formation of shock waves in a Bose-Einstein condensate containing a large number of sodium atoms. The shock wave is initiated with a repulsive, blue-detuned light barrier, intersecting the BEC, after which two shock fronts appear. We observe breaking of these waves when the size of these waves approaches the healing length of the condensate. At this time, the wave front splits into two parts and clear fringes appear. The experiment is modeled using an effective 1D Gross-Pitaevskii-like equation and gives excellent quantitative agreement with the experiment, even though matter waves with wavelengths two orders of magnitude smaller than the healing length are present. In these experiments, no significant heating or particle loss is observed.