Momentum distribution of a Fermi gas of atoms in the BCS-BEC crossover.
We observe dramatic changes in the atomic momentum distribution of a Fermi gas in the crossover region between the BCS theory superconductivity and Bose-Einstein condensation (BEC) of molecules. We study the shape of the momentum distribution and the kinetic energy as a function of interaction strength. The momentum distributions are compared to a mean-field crossover theory, and the kinetic energy is compared to theories for the two weakly interacting limits. This measurement provides a unique probe of pairing in a strongly interacting Fermi gas.
Regal
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JILA, Quantum Physics Division, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA. regal@jilau.colorado.edu
Greiner
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Giorgini
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Holland
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Jin
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