title: Tuning the mobility of a driven Bose-Einstein condensate via diabatic Floquet bands.
abstract: We study the response of ultracold atoms to a weak force in the presence of a temporally strongly modulated optical lattice potential. It is experimentally demonstrated that the strong ac driving allows for a tailoring of the mobility of a dilute atomic Bose-Einstein condensate with the atoms moving ballistically either along or against the direction of the applied force. Our results are in agreement with a theoretical analysis of the Floquet spectrum of a model system, thus revealing the existence of diabatic Floquet bands in the atoms' band spectra and highlighting their role in the nonequilibrium transport of the atoms.
authors.affiliation: Institut für Angewandte Physik der Universität Bonn, Wegelerstrasse 8, 53115 Bonn, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Salger
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kling
authors.forename: Sergey
authors.initials: S
authors.lastname: Denisov
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Ponomarev
authors.forename: Peter
authors.initials: P
authors.lastname: Hänggi
authors.forename: Martin
authors.initials: M
authors.lastname: Weitz