A Bose-Einstein condensate of metastable atoms.
We report the realization of a Bose-Einstein condensate of metastable atoms (helium in the lowest triplet state). The excitation energy of each atom with respect to the ground state is 20 electron volts, but inelastic processes that would destroy the sample are suppressed strongly enough in a spin-polarized sample to allow condensation. Our detection scheme takes advantage of the metastability to achieve detection of individual atoms as well as of the decay products of inelastic processes. This detection opens the way toward new studies in mesoscopic quantum statistical physics, as well as in atomic quantum optics.
Robert
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Laboratoire Charles Fabry de l'Institut d'Optique, UMR 8501 du CNRS, Bâtiment 503, Campus Universitaire d'Orsay, Boite Postale 147, F-91403 Orsay Cedex, France.
Sirjean
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Browaeys
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Poupard
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Nowak
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Boiron
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Westbrook
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Aspect
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