2008/09/10 by Shizhong Zhang, Anthony J. Leggett
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Quantum, superfluid, helium dynamics #Strong Light-Matter Interactions #cond-mat.str-el
paper · pdf · doi:10.1103/physreva.79.023601
arxiv created 2008/09/10 · openalex publication_date 2009/02/02 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present some general considerations on the properties of a two-component ultracold Fermi gas along the BEC-BCS crossover. It is shown that the interaction energy and the free energy can be written in terms of a single dimensionless function h(\ensuremathξ,\ensuremathτ), where \ensuremathξ=\ensuremath-(kFas)^\ensuremath-1 and \ensuremathτ=T∕TF. The function h(\ensuremathξ,\ensuremathτ) incorporates all the many-body physics and naturally occurs in other physical quantities as well. In particular, we show that the average rf-spectroscopy shift \ensuremathδ\ensuremathω(\ensuremathξ,\ensuremathτ) and the molecular fraction fc(\ensuremathξ,\ensuremathτ) in the closed channel can be expressed in terms of h(\ensuremathξ,\ensuremathτ) and thus have identical temperature dependence. The conclusions should have testable consequences in future experiments.