Resonance States and Quantum Tunneling of Bose Einstein condensates in a 3D shallow trap

TL;DR

This paper investigates the resonance states and quantum tunneling phenomena of Bose-Einstein condensates in realistic 3D shallow traps using a correlated many-body approach, revealing new metastable states and decay behaviors.

Contribution

It introduces a realistic modeling of BEC resonance states in shallow traps with van der Waals interactions, discovering a new metastable branch not seen in harmonic traps.

Findings

Identification of a new metastable branch in shallow traps.

Calculation of decay rates for the lowest quasi-bound state.

Observation of the disappearance of the metastable branch with increasing particle number.

Abstract

A correlated quantum many-body method is applied to describe resonance states of atomic Bose-Einstein condensates (BEC) in a realistic shallow trap (as opposed to infinite traps commonly used). The realistic van der Waals interaction is adopted as the interatomic interaction. We calculate experimentally measurable decay rates of the lowest quasi-bound state in the shallow trap. The most striking result is the observation of a new metastable branch besides the usual one for attractive BEC in a pure harmonic trap. As the particle number increases the new metastable branch appears, then gradually disappears and finally usual metastable branch (associated with the attractive BEC in a harmonic trap) appears, eventually leading to the collapse of the condensate.