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arXiv · 0710.5083

Control of Interaction-Induced Dephasing of Bloch Oscillations

M. Gustavsson·E. Haller·M. J. Mark·J. G. Danzl·G. Rojas-Kopeinig·H. -C. Naegerl
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Abstract

We report on the control of interaction-induced dephasing of Bloch oscillations for an atomic Bose-Einstein condensate in an optical lattice under the influence of gravity. When tuning the strength of the interaction towards zero by means of a Feshbach resonance, the dephasing time is increased from a few to more than twenty thousand Bloch oscillation periods. We quantify the dephasing in terms of the width of the quasi-momentum distribution and measure its dependence on time for different values of the scattering length. Minimizing the dephasing allows us to realize a BEC-based atom interferometer in the non-interacting limit. We use it for a precise determination of a zero-crossing for the atomic scattering length and to observe collapse and revivals of Bloch oscillations when the atomic sample is subject to a spatial force gradient.

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M. Gustavsson, E. Haller, M. J. Mark, J. G. Danzl, G. Rojas-Kopeinig, H. -C. Naegerl. 2007-10-26. Control of Interaction-Induced Dephasing of Bloch Oscillations. https://doi.org/10.1103/physrevlett.100.080404

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