2009/05/12 by Zhenhua Yu, Georg M. Bruun, Gordon Baym · 1 citation
Chemistry · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Quantum, superfluid, helium dynamics #Spectroscopy and Laser Applications #cond-mat.other #cond-mat.quant-gas
paper · pdf · doi:10.1103/physreva.80.023615
published as Phys. Rev. A 80, 023615 (2009). · 6 pages, 3 figures
arxiv created 2009/05/12 · openalex publication_date 2009/08/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We relate short-range correlations in ultracold-atom Fermi gases to the entropy of the system over the entire temperature, T, vs coupling strength, \ensuremath-1/kFa, plane. In the low-temperature limit the entropy is dominated by phonon excitations and the correlations increase as T4. In the Bose-Einstein condensate (BEC) limit, we calculate a boson model within the Bogoliubov approximation to show explicitly how phonons enhance the fermion correlations. In the high-temperature limit, we show from the virial expansion that the correlations decrease as 1/T. The correlations therefore reach a maximum at a finite-temperature. We infer the general structure of the isentropes of the Fermi gas in the (T,\ensuremath-1/kFa) plane, and the temperature dependence of the correlations in the unitary, BEC, and BCS limits. Our results compare well with measurements of the correlations via photoassociation experiments at higher temperatures.