title: Experimental realization of quantum-resonance ratchets at arbitrary quasimomenta.
abstract: Quantum-resonance ratchets associated with the kicked particle are experimentally realized for arbitrary quasimomentum using a Bose-Einstein condensate (BEC) exposed to a pulsed standing light wave. The ratchet effect for general quasimomentum arises even though both the standing-wave potential and the initial state of the BEC have a point symmetry. The experimental results agree well with theoretical ones which take into account the finite quasimomentum width of the BEC. In particular, this width is shown to cause a suppression of the ratchet acceleration for exactly resonant quasimomentum, leading to a saturation of the directed current.
authors.affiliation: Minerva Center and Department of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel.
authors.forename: I
authors.initials: I
authors.lastname: Dana
authors.forename: V
authors.initials: V
authors.lastname: Ramareddy
authors.forename: I
authors.initials: I
authors.lastname: Talukdar
authors.forename: G S
authors.initials: GS
authors.lastname: Summy