title: Momentum distribution of a Fermi gas of atoms in the BCS-BEC crossover.
abstract: 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.
authors.affiliation: JILA, Quantum Physics Division, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA. regal@jilau.colorado.edu
authors.forename: C A
authors.initials: CA
authors.lastname: Regal
authors.forename: M
authors.initials: M
authors.lastname: Greiner
authors.forename: S
authors.initials: S
authors.lastname: Giorgini
authors.forename: M
authors.initials: M
authors.lastname: Holland
authors.forename: D S
authors.initials: DS
authors.lastname: Jin