Self-consistent effects of continuous wave output coupling of atoms from a Bose-Einstein condensate

TL;DR

This paper develops a self-consistent mean field model for continuous wave atom laser output coupling from Bose-Einstein condensates, analyzing atom flow effects in different atomic species and their impact on condensate stability.

Contribution

It introduces a modified Hartree-Fock Bogoliubov model with spatial source and sink terms to study atom extraction in BECs, including effects of current flow on stability.

Findings

Flow can stabilize attractive BECs against instability.

Kinetic energy from flow influences condensate dynamics.

Model applies to Rubidium and Lithium condensates.

Abstract

We present a self-consistent mean field model of the extraction of atoms from a Bose-Einstein condensate to form a CW atom laser. The model is based upon the Hartree-Fock Bogoliubov equations within the Popov approximation, modified by the inclusion of spatially dependent source and sink terms, which lead to current flow within the condensate. The effects of this current flow are investigated for traps containing Rubidium (repulsive effective interaction) and Lithium (attractive interaction) atoms. The extra kinetic energy associated with this flow is shown to be able to stabilise the condensate in the attractive case against mechanical instability.