Stability of excited states of a Bose-Einstein condensate in an anharmonic trap

TL;DR

This paper investigates how the stability of excited nonlinear states in a Bose-Einstein condensate is affected by the shape of the trapping potential, showing increased stability in anharmonic traps compared to harmonic ones.

Contribution

It provides a detailed analysis of the stability of nonlinear excited states in 1D Bose-Einstein condensates within anharmonic traps, highlighting the stabilizing effect of anharmonicity.

Findings

Nonlinear states are more stable in anharmonic traps.

Harmonic traps with equidistant spectra are less stable.

Stability increases when switching from harmonic to anharmonic potentials.

Abstract

We analyze the stability of non-ground nonlinear states of a Bose-Einstein condensate in the mean field limit in effectively 1D (``cigar-shape'') traps for various types of confining potentials. We find that nonlinear states become, in general, more stable when switching from a harmonic potential to an anharmonic one. We discuss the relation between this fact and the specifics of the harmonic potential which has an equidistant spectrum.