title: Directed motion for delta-kicked atoms with broken symmetries: comparison between theory and experiment.
abstract: We report an experimental investigation of momentum diffusion in the delta-function kicked rotor where time symmetry is broken by a two-period kicking cycle and spatial symmetry by an alternating linear potential. We exploit this, and a technique involving a moving optical potential, to create an asymmetry in the momentum diffusion that is due to the classical chaotic diffusion. This represents a realization of a type of Hamiltonian quantum ratchet.
authors.affiliation: Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
authors.forename: P H
authors.initials: PH
authors.lastname: Jones
authors.forename: M
authors.initials: M
authors.lastname: Goonasekera
authors.forename: D R
authors.initials: DR
authors.lastname: Meacher
authors.forename: T
authors.initials: T
authors.lastname: Jonckheere
authors.forename: T S
authors.initials: TS
authors.lastname: Monteiro