title: Momentum distribution and contact of the unitary Fermi gas.
abstract: We calculate the momentum distribution n(k) of the unitary Fermi gas by using quantum Monte Carlo calculations at finite temperature T/ϵ(F) as well as in the ground state. At large momenta k/k(F), we find that n(k) falls off as C/k⁴, in agreement with the Tan relations. From the asymptotics of n(k), we determine the contact C as a function of T/ϵ(F) and present a comparison with theory. At low T/ϵ(F), we find that C increases with temperature, and we tentatively identify a maximum around T/ϵ(F) ≃ 0.4. Our calculations are performed on lattices of spatial extent up to N(x) = 14 with a particle number per unit volume of ≃ 0.03-0.07.
authors.affiliation: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545-0001, USA.
authors.forename: Joaquín E
authors.initials: JE
authors.lastname: Drut
authors.forename: Timo A
authors.initials: TA
authors.lastname: Lähde
authors.forename: Timour
authors.initials: T
authors.lastname: Ten