Interaction induced trapping and pulsed emission of a magnetically insensitive Bose-Einstein Condensate

TL;DR

This paper demonstrates that magnetically insensitive atoms can be trapped using a magnetically trapped Bose-Einstein Condensate, revealing interaction-induced trapping, inhibited hyperfine transitions at low densities, and pulsed atom emission akin to an atom laser.

Contribution

It introduces a novel method for trapping magnetically insensitive atoms via interactions with a magnetically trapped BEC, and explores controlled outcoupling and pulsed emission phenomena.

Findings

Magnetically insensitive atoms can be trapped by a BEC of different hyperfine states.

Hyperfine state changing collisions are suppressed at low densities.

Pulsed atom emission observed, similar to an atom laser.

Abstract

We demonstrate that atoms in magnetically insensitive hyperfine states (m=0) can be trapped efficiently by a Bose-Einstein Condensate of the same atomic species occupying a different hyperfine state. The latter is trapped magnetically. Hyperfine state changing collisions, and therefore loss of the trapped (m=0) atoms, are shown to be strongly inhibited in case of a low density of the confined atomic cloud. We monitor the transition from a 'soft' to a 'hard' effective potential by studying the backaction of the trapped (m=0) atoms onto the condensate which provides their confinement. The controlled outcoupling of the trapped atoms by shaping the condensate's wavefunction is explored. We observe a pulsed emission of atoms from the trapping region reminiscent of an atom laser.