title: Bose-Einstein condensation into nonequilibrium States studied by condensate focusing.
abstract: We report the formation of Bose-Einstein condensates into nonequilibrium states. Our condensates are much longer than equilibrium condensates with the same number of atoms, show strong phase fluctuations, and have a dynamical evolution similar to that of quadrupole shape oscillations of regular condensates. The condensates emerge in elongated traps as the result of local thermalization when the nucleation time is short compared to the axial oscillation time. We introduce condensate focusing as a new method to extract the phase-coherence length of Bose-Einstein condensates.
authors.affiliation: FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
authors.forename: I
authors.initials: I
authors.lastname: Shvarchuck
authors.forename: Ch
authors.initials: Ch
authors.lastname: Buggle
authors.forename: D S
authors.initials: DS
authors.lastname: Petrov
authors.forename: K
authors.initials: K
authors.lastname: Dieckmann
authors.forename: M
authors.initials: M
authors.lastname: Zielonkowski
authors.forename: M
authors.initials: M
authors.lastname: Kemmann
authors.forename: T G
authors.initials: TG
authors.lastname: Tiecke
authors.forename: W
authors.initials: W
authors.lastname: von Klitzing
authors.forename: G V
authors.initials: GV
authors.lastname: Shlyapnikov
authors.forename: J T M
authors.initials: JT
authors.lastname: Walraven