Nonlocal interactions prevent collapse in negative scattering length Bose-Einstein gases

TL;DR

This paper demonstrates that nonlocal interactions in Bose-Einstein condensates with negative scattering length prevent collapse, leading to oscillations and stable localized wave packets instead.

Contribution

It provides evidence that finite-range nonlocal interactions inhibit collapse in Bose-Einstein condensates with negative scattering length, a novel insight into stability mechanisms.

Findings

Nonlocality prevents collapse in negative scattering length condensates.

Oscillations of wave packets occur with sizes comparable to interaction range.

Finite-range interactions lead to stable localized states instead of collapse.

Abstract

We study the effect of nonlocality on the collapse properties of a self-focusing Nonlinear Schr\"odinger system related to Bose-Einstein condensation problems. Using a combination of moment techniques, time dependent variational methods and numerical simulations we present evidences in support of the hypothesis that nonlocal attractively interacting condensates cannot collapse when the dominant interaction term is due to finite range interactions. Instead there apppear oscillations of the wave packet with a localized component whose size is of the order of the range of interactions. We discuss the implications of the results to collapse phenomena in negative scattering length Bose-Einstein condensates.