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

¹  Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg - INF 229, 69120 Heidelberg, Germany, EU
²  Institut für Theoretische Physik, Universität Innsbruck - Innsbruck, Austria, EU
³  Physikalisches Institut, Universität Heidelberg - Philosophenweg 12, 69120 Heidelberg, Germany, EU

Corresponding author: stephan.middelkamp@pci.uni-heidelberg.de

Received: 22 July 2008
Accepted: 16 October 2008

Abstract

We demonstrate that atoms in magnetically insensitive hyperfine states () 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 () 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 () atoms onto the condensate which provides their confinement. The controlled outcoupling of the trapped atoms by shaping the condensate wave function is explored. We observe a pulsed emission of atoms from the trapping region reminiscent of an atom laser.