2005/04/27 by Georg M. Bruun, G. M. Bruun, H. Smith · 3 citations
Physics and Astronomy · #Atomic and Subatomic Physics Research #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Fermi gas #Fermion #Instability #Physics #Quantum mechanics #Quantum, superfluid, helium dynamics #Relaxation (psychology) #Scattering #Scattering length #Superfluidity #Thermodynamics #Unitarity #Viscosity #cond-mat.stat-mech #hep-ph
paper · pdf · doi:10.1103/physreva.72.043605
published as Phys.Rev. A72 (2005) 043605 · 7 pages, 3 figures
arxiv created 2005/04/27 · openalex publication_date 2005/10/13 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
The viscous and thermal relaxation rates of an interacting fermion gas are calculated as functions of temperature and scattering length, using a many-body scattering matrix which incorporates medium effects due to Fermi blocking of intermediate states. These effects are demonstrated to be large close to the transition temperature Tc to the superfluid state. For a homogeneous gas in the unitarity limit, the relaxation rates are increased by nearly an order of magnitude compared to their value obtained in the absence of medium effects due to the Cooper instability at Tc. For trapped gases the corresponding ratio is found to be about three due to the averaging over the inhomogeneous density distribution. The effect of superfluidity below Tc is considered to leading order in the ratio between the energy gap and the transition temperature.