Formation of shock waves in a Bose-Einstein condensate

TL;DR

This paper investigates how density wave packets evolve in a Bose-Einstein condensate, demonstrating shock wave formation and providing insights for experimental measurement of sound speed, while discussing the limitations of mean-field models.

Contribution

It presents a detailed analysis of shock wave formation in BECs beyond zero-amplitude approximations, offering a new approach for experimental data interpretation.

Findings

Shock waves form from broad density perturbations in BECs.

The shape evolution of density waves can be used to measure the speed of sound.

Limitations of mean-field theory are discussed in the context of shock phenomena.

Abstract

We consider propagation of density wave packets in a Bose-Einstein condensate. We show that the shape of initially broad, laser-induced, density perturbation changes in the course of free time evolution so that a shock wave front finally forms. Our results are well beyond predictions of commonly used zero-amplitude approach, so they can be useful in extraction of a speed of sound from experimental data. We discuss a simple experimental setup for shock propagation and point out possible limitations of the mean-field approach for description of shock phenomena in a BEC.