Coherence length of an elongated condensate

Phase coherence length of an elongated Bose-Einstein condensate

Coherence length of an elongated condensate: a study by matter-wave interferometry

We measure the spatial correlation function of Bose-Einstein condensates in the cross-over region between phase-coherent and strongly phase-fluctuating condensates. We observe the continuous path from a gaussian-like shape to an exponential-like shape characteristic of one-dimensional phase-fluctuations. The width of the spatial correlation function as a function of the temperature shows that t...

Landau damping of transverse quadrupole oscillations of an elongated Bose-Einstein condensate

M. Guilleumas and L. P. Pitaevskii Departament d’Estructura i Constituents de la Matèria, Facultat de Fı́sica, Universitat de Barcelona, E-08028 Barcelona, Spain Dipartimento di Fisica, Università di Trento and Istituto Nazionale per la Fisica della Materia, I-38050 Povo, Italy Kapitza Institute for Physical Problems, 117454 Moscow, Russian Federation ~Received 4 August 2002; published 27 May 2003!

Suppression of transport of an interacting elongated Bose-Einstein condensate in a random potential.

We observe the suppression of the 1D transport of an interacting elongated Bose-Einstein condensate in a random potential with an amplitude that is small compared to the typical energy per atom, dominated by the interaction energy. Numerical calculations reproduce our observations well. We propose a scenario for disorder-induced trapping of the condensate in agreement with our findings.

Directional "superradiant" collisions: bosonic amplification of atom pairs emitted from an elongated Bose-Einstein condensate.

We study spontaneous directionality in the bosonic amplification of atom pairs emitted from an elongated Bose-Einstein condensate, an effect analogous to superradiant emission of atom-photon pairs. Using a simplified model, we make analytic predictions regarding directional effects for both atom-atom and atom-photon emission. These are confirmed by numerical mean-field simulations, demonstratin...