2005/12/22 by V. S. Shchesnovich, Valery S. Shchesnovich, Shchesnovich, Valery S. +3
Chemistry · Physics and Astronomy · #Atomic Physics (physics.atom-ph) #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Other Condensed Matter (cond-mat.other) #Quantum Physics (quant-ph) #Semiconductor Quantum Structures and Devices #Spectroscopy and Laser Applications #cond-mat.other #physics.atom-ph #quant-ph
paper · pdf · doi:10.48550/arxiv.cond-mat/0512565
23 pages, 7 figures. Revised section V and changed figure 7. To appear in J. Phys. B: Atomic, Molecular and Optical Physics
openalex publication_date 2005/12/22 · arxiv created 2006/03/18 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We derive a two-band finite-dimensional model for description of the condensate tunneling in an accelerating optical lattice, taking into account the fine Bloch band structure. The model reveals a very strong dependence of the final band populations on the initial populations and phases. Most importantly, additionally to the known asymmetric dependence on the nonlinearity, there is also a notable asymmetry in the sensitivity of the tunneling probability to the nonliearity-induced initial population of the Bloch band to which the tunneling takes place. This fact can explain the experimentally observed unexpected independence of the upper-to-lower tunneling probablity on the nonlinearity. Finally, we compare the predictions of the two-band model with that of the well-known nonlinear Landau-Zener model and find disagreement when the two bands are initially populated. The disagreement can be qualitative and reveals itself even for a negligible nonlinearity. However, the two models agree remarkably well if just one band is populated initially.