Momentum distribution and condensate fraction of a fermion gas in the BCS-BEC crossover.
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.
Astrakharchik
G E
GE
Dipartimento di Fisica and BEC-INFM, Università di Trento, I-38050 Povo, Italy.
Boronat
J
J
Casulleras
J
J
Giorgini
S
S