Hannover 2010 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 38: Quantum Gases: Bosons III / Lattices I
Q 38.10: Vortrag
Mittwoch, 10. März 2010, 18:45–19:00, E 001
Enhancement and suppression of the Landau-Zener tunneling in the presence of time-dependent disorder — •Ghazal Tayebirad1,2 and Sandro Wimberger1,2 — 1Institüt für Theoretische Physik, Universität Heidelberg, Philosophenweg 19, D-69120 — 2Heidelberg Graduate School of Fundamental Physics, Albert-Ueberle-Str. 3-5, D-69120
We investigate the coherent control of the transport and of the decay of Bose-Einstein condensates from the ground band in a lattice structure with time-dependent disorder. To this respect, we study the time evolution of ultra-cold atoms loaded into a quasi-1D geometry supporting a stochastic potential and subjected to an additional static force. Our disordered lattice can be created by superimposing two standing waves with incommensurable wavelengths which have a time-dependent random phase shift with respect to each other. We demonstrate that stochastic noise [1] in the system can be used to engineer the transport of ultra-cold atoms without changing system intrinsic parameters. Our results show how an appropriately chosen random phase either enhances, suppresses, or hardly affects the Landau-Zener tunneling out of the ground band of the lattice.
[1] R. Mannella, A gentle introduction to the integration of stochastic differential equations, Lecture Notes in Physics, 557 (Springer, Heidelberg, 2000)