Experiments with a Bose-Einstein condensate in a quasi-one-dimensional magnetic waveguide

Yi Zheng

J. Fort�gh, Herwig Ott, Sebastian Kraft +2 more

Daw-Wei Wang, Mikhail D. Lukin, Eugene Demler

We analyze the effects of a random magnetic potential in a microfabricated waveguide for ultracold atoms. We find that the shape and position fluctuations of a current carrying wire induce a strong Gaussian correlated random potential with a length scale set by the atom-wire separation. The theory is used to explain quantitatively the observed fragmentation of the Bose-Einstein condensates in atomic waveguides. Furthermore, we show that nonlinear dynamics can be used to provide important insights into the nature of the strongly fragmented condensates. We argue that a quantum phase transition from the superfluid to the insulating Bose glass phase may be reached and detected under the realistic experimental conditions.

A. Couvert, Matthew Jeppesen, Tomasz Kawalec +3 more

We report the achievement of an optically guided and quasi-monomode atom laser, in all spin projection states ( m F =-1, 0 and +1) of F =1 in rubidium 87. The atom laser source is a Bose-Einstein condensate (BEC) in a crossed dipole trap, purified to any one spin projection state by a spin-distillation process applied during the evaporation to BEC. The atom laser is outcoupled by an inhomogenous magnetic field, applied along the waveguide axis. The mean excitation number in the transverse modes is ⟨ n ⟩=0.65±0.05 for m F =0 and ⟨ n ⟩=0.8±0.3 for the low-field seeker m F =-1. Using a simple thermodynamical model, we infer from our data the population in each excited mode.

Claus Zimmermann, József Fortágh, Herwig Ott +2 more

Dan Stamper-Kurn, Dallin Durfee, M.‐O. Mewes +3 more