Stability of spherically trapped three-dimensional Bose-Einstein condensates against macroscopic fragmentation

TL;DR

This paper investigates the stability of three-dimensional Bose-Einstein condensates against macroscopic fragmentation, finding that they are more stable than lower-dimensional counterparts but can fragment at high interaction strengths.

Contribution

It provides a detailed analysis of the stability threshold for 3D Bose-Einstein condensates against fragmentation, combining numerical and semi-analytical methods.

Findings

3D condensates are more stable than quasi-1D and quasi-2D.

Fragmentation occurs at high interaction measures.

Stability threshold is determined numerically and analytically.

Abstract

We consider spherically trapped Bose gases in three dimensions with contact interactions, and investigate whether the Bose-Einstein condensate at zero temperature is stable against macroscopic fragmentation into a small number of mutually incoherent pieces. Our results are expressed in terms of a dimensionless interaction measure proportional to the Thomas-Fermi parameter. It is shown that while three-dimensional condensates are inherently much more stable against macroscopic fragmentation than their quasi-one- and quasi-two-dimensional counterparts, they fragment at a sufficiently large value of the dimensionless interaction measure, which we determine both fully numerically and semianalytically from a continuum limit of large particle numbers.