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Experimental evidence for the breakdown of a Hartree-Fock approach in a weakly interacting Bose gas

Jean-Baptiste Trebbia·Jérôme Estève·Christoph I. Westbrook·Isabelle Bouchoule
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Abstract

We study the formation of a quasi-condensate in a nearly one dimensional, weakly interacting trapped atomic Bose gas. We show that a Hartree Fock (mean-field) approach fails to explain the presence of the quasi-condensate in the center of the cloud: the quasi-condensate appears through an interaction-driven cross-over and not a saturation of the excited states. Numerical calculations based on Bogoliubov theory give an estimate of the cross-over density in agreement with experimental results.

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Jean-Baptiste Trebbia, Jérôme Estève, Christoph I. Westbrook, Isabelle Bouchoule. 2006-06-30. Experimental evidence for the breakdown of a Hartree-Fock approach in a weakly interacting Bose gas. https://doi.org/10.1103/physrevlett.97.250403

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