Macroscopic quantum tunnelling of a Bose-Einstein condensate in a Cubic-Plus-Quadratic Well

Abstract

We study the macroscopic quantum tunnelling of an interacting Bose-Einstein condensate in a cubic-plus-quadratic well that was approximately realized in recent experiment. We utilise the Gross-Pitaevskii equation and Wentzel-Kramers-Brillouin (WKB) method to investigate the effect of the inter-atomic interactions on the tunnelling rate of a quasi-bound condensate. We find that the existence of repulsive interaction enhances the quantum tunnelling of a trapped Bose-Einstein condensate.