Dynamics of a BEC bright soliton in an expulsive potential

TL;DR

This paper models the behavior of a Bose-Einstein condensate bright soliton in an expulsive potential using an effective one-dimensional equation, successfully matching experimental observations.

Contribution

It introduces a non-polynomial Schrödinger equation derived from the 3D Gross-Pitaevskii equation to accurately describe BEC soliton dynamics in an expulsive potential.

Findings

The effective 1D equation reproduces main experimental features.

The model captures the soliton's stability and dynamics.

Agreement with experimental data confirms the model's validity.

Abstract

We theoretically investigate the dynamics of a matter-wave soliton created in a harmonic potential, which is attractive in the transverse direction but expulsive in the longitudinal direction. This Bose-Einstein-condensate (BEC) bright soliton made of $^7$Li atoms has been observed in a recent experiment (Science {\bf 296}, 1290 (2002)). We show that the non-polynomial Schr\"odinger equation, an effective one-dimensional equation we derived from the three-dimensional Gross-Pitaevskii equation, is able to reproduce the main experimental features of this BEC soliton in an expulsive potential.