Observing collapse in two colliding dipolar Bose-Einstein condensates

TL;DR

This paper investigates how two colliding dipolar Bose-Einstein condensates can undergo collapse due to local density fluctuations, even when the total atom number is below the critical threshold, using detailed 3D simulations.

Contribution

It demonstrates collapse mechanisms during condensate collisions caused by local density fluctuations, providing detailed simulation data relevant for future experimental studies.

Findings

Collapse occurs during collision due to local density fluctuations.

Density distribution and energy evolve dynamically during collision.

Collapse time depends on the relative phase between condensates.

Abstract

We study the collision of two Bose-Einstein condensates with pure dipolar interaction. A stationary pure dipolar condensate is known to be stable when the atom number is below a critical value. However, collapse can occur during the collision between two condensates due to local density fluctuations even if the total atom number is only a fraction of the critical value. Using full three-dimensional numerical simulations, we observe the collapse induced by local density fluctuations. For the purpose of future experiments, we present the time dependence of the density distribution, energy per particle and the maximal density of the condensate. We also discuss the collapse time as a function of the relative phase between the two condensates.