2008/03/31 by Jian Deng, Jincheng Wang, Jin-cheng Wang +1
Physics and Astronomy · #Bose–Einstein condensate #Boson #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Cooper pair #Crossover #Fermion #Mean field theory #Pairing #Physics #Physics of Superconductivity and Magnetism #Quantum electrodynamics #Quantum mechanics #Quantum, superfluid, helium dynamics #Superconductivity #Superfluidity #hep-ph
paper · pdf · doi:10.1103/physrevd.78.034014
published as Phys.Rev.D78:034014,2008 · The model Lagrangian is re-formulated by decomposing the complex scalar field into its real and imaginary parts. The anomalous propagators of the complex scalar are then included at tree level. All numerical results are updated. ReVTex 4, 13 pages, 10 figures, PRD accepted version
arxiv created 2008/07/21 · openalex publication_date 2008/08/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the fluctuation effect of the di-fermion field in the crossover from Bardeen-Cooper-Schrieffer (BCS) pairing to a Bose-Einstein condensate (BEC) in a relativistic superfluid. We work within the boson-fermion model obeying a global U(1) symmetry. To go beyond the mean field approximation we use Cornwall-Jackiw-Tomboulis formalism to include higher-order contributions. The quantum fluctuations of the pairing condensate is provided by bosons in nonzero modes, whose interaction with fermions gives the two-particle-irreducible effective potential. It changes the crossover property in the BEC regime. With the fluctuations the superfluidity phase transition becomes the first order in a grand canonical ensemble. We calculate the condensate, the critical temperature Tc and particle abundances as functions of a crossover parameter of the boson mass.