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Second Order Correlation Function of a Phase Fluctuating Bose-Einstein Condensate

L. Cacciapuoti·D. Hellweg·M. Kottke·T. Schulte·K. Sengstock·W. Ertmer·J. J. Arlt·L. Santos·M. Lewenstein
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Abstract

The coherence properties of phase fluctuating Bose-Einstein condensates are studied both theoretically and experimentally. We derive a general expression for the N-particle correlation function of a condensed Bose gas in a highly elongated trapping potential. The second order correlation function is analyzed in detail and an interferometric method to directly measure it is discussed and experimentally implemented. Using a Bragg diffraction interferometer, we measure intensity correlations in the interference pattern generated by two spatially displaced copies of a parent condensate. Our experiment demonstrates how to characterize the second order correlation function of a highly elongated condensate and to measure its phase coherence length.

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L. Cacciapuoti, D. Hellweg, M. Kottke, T. Schulte, K. Sengstock, W. Ertmer, J. J. Arlt, L. Santos, M. Lewenstein. 2003-08-07. Second Order Correlation Function of a Phase Fluctuating Bose-Einstein Condensate. https://doi.org/10.1103/physreva.68.053612

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