Number of closed-channel molecules in the BEC-BCS crossover
Laboratoire Kastler Brossel, École Normale Supérieure, UPMC and CNRS, 24 rue Lhomond, 75231 Paris Cedex 05, France
Corresponding author: a firstname.lastname@example.org
Revised: 9 December 2008
Published online: 10 February 2009
Using a two-channel model, we show that the number of closed-channel molecules in a two-component Fermi gas close to a Feshbach resonance is directly related to the derivative of the energy of the gas with respect to the inverse scattering length. We extract this quantity from the fixed-node Monte Carlo equation of state and we compare to the number of closed-channel molecules measured in the Rice experiment with lithium [Partridge et al., Phys. Rev. Lett. 95, 020404 (2005)]. We also discuss the effect of a difference between the trapping potentials seen by a closed-channel molecule and by an open-channel pair of atoms in terms of an effective position-dependent scattering length.
PACS: 03.75.Ss – Degenerate Fermi gases / 67.90.+z – Other topics in quantum fluids and solids
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2009