title: Momentum distribution and condensate fraction of a fermion gas in the BCS-BEC crossover.
abstract: By using the diffusion Monte Carlo method we calculate the one- and two-body density matrix of an interacting Fermi gas at T = 0 in the BCS to Bose-Einstein condensate (BEC) crossover. Results for the momentum distribution of the atoms, as obtained from the Fourier transform of the one-body density matrix, are reported as a function of the interaction strength. Off-diagonal long-range order in the system is investigated through the asymptotic behavior of the two-body density matrix. The condensate fraction of pairs is calculated in the unitary limit and on both sides of the BCS-BEC crossover.
authors.affiliation: Dipartimento di Fisica and BEC-INFM, Università di Trento, I-38050 Povo, Italy.
authors.forename: G E
authors.initials: GE
authors.lastname: Astrakharchik
authors.forename: J
authors.initials: J
authors.lastname: Boronat
authors.forename: J
authors.initials: J
authors.lastname: Casulleras
authors.forename: S
authors.initials: S
authors.lastname: Giorgini