Mean Field Calculations of Bose-Einstein Condensation of 7Li Atoms In a Harmonic Trap

TL;DR

This paper develops a mean-field theory to model Bose-Einstein condensation of 7Li atoms in a harmonic trap, reconciling theoretical predictions with experimental observations, and analyzing stability and collapse phenomena.

Contribution

It introduces a self-consistent mean-field approach including anisotropic traps and atom interactions, providing insights into collapse and condensation behavior.

Findings

Predicted localized condensate near critical temperature

Numerical instability indicates collapse at lower temperatures

Reconciles theoretical models with experimental observations

Abstract

A self-consistent mean-field theory for bosons for T>0 is used to reconcile predictions of collapse with recent observations of Bose-Einstein condensation of 7Li. Eigenfunctions of a (non-separable) Hamiltonian that includes the anisotropic external trap field and atom-atom interactions are obtained by an iteration process. A sum over the Bose distribution, and the ``alternating direction implicit'' algorithm are used. Near Tc, the ensemble exhibits a localized condensate composed of atoms in the few lowest states. For lower T, numerical instability indicates collapse to a more dense phase.