Dynamics of Bose-Einstein condensates under anharmonic trap

TL;DR

This paper investigates how anharmonic distortions in trapping potentials affect the dynamics, stability, and oscillation modes of Bose-Einstein condensates using variational and numerical methods.

Contribution

It introduces a variational approach to derive coupled width equations and analyzes the effects of anharmonic distortions on BEC dynamics and stability.

Findings

Anharmonic distortions influence mode coupling and resonances.

Small anharmonic distortions can extend or reduce condensate stability.

Stability regions depend on the nature of anharmonic distortion.

Abstract

The dynamics of weakly interacting three-dimensional Bose-Einstein condensates (BECs), trapped in external axially symmetric plus anharmonic distortion potential are studied. Within a variational approach and time-dependent Gross-Pitaevskii equation, the coupled condensate width equations are derived. By modulating anharmonic distortion of the trapping potential, nonlinear features are studied numerically and illustrated analytically, such as mode coupling of oscillation modes, and resonances. Furthermore, the stability of attractive interaction BEC in both repulsive and attractive anharmonic distortion is examined. We demonstrate that a small repulsive and attractive anharmonic distortion is effective in reducing (extending) the condensate stability region since it decreases (increases) the critical number of atoms in the trapping potential.