arXiv:0707.1980 · Physical Review Letters
Atomic Landau-Zener Tunneling in Fourier-Synthesized Optical Lattices
Tobias Salger, Carsten Geckeler, Sebastian Kling, Martin Weitz
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.