title: Atomic Landau-Zener tunneling in Fourier-synthesized optical lattices.
abstract: We report on an experimental study of quantum transport of atoms in variable periodic optical potentials. The band structure of both ratchet-type asymmetric and symmetric lattice potentials is explored. The variable atom potential is realized by superimposing a conventional standing wave potential of lambda/2 spatial periodicity with a fourth-order multiphoton potential of lambda/4 periodicity. We find that the Landau-Zener tunneling rate between the first and the second excited Bloch band depends critically on the relative phase between the two spatial lattice harmonics.
authors.affiliation: Institut für Angewandte Physik, Universität Bonn, Wegelerstr, 8, D-53115, Bonn, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Salger
authors.forename: Carsten
authors.initials: C
authors.lastname: Geckeler
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kling
authors.forename: Martin
authors.initials: M
authors.lastname: Weitz