BCS-BEC crossover in a relativistic boson-fermion model beyond mean field approximation

Journal Article · Fri Aug 01 00:00:00 EDT 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.78.034014· OSTI ID:21250618

Jian, Deng; Jincheng, Wang; Qun, Wang ^[1]

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1. Interdisciplinary Center for Theoretical Study and Department of Modern Physics, University of Science and Technology of China, Anhui 230026 (China)

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 T{sub c} and particle abundances as functions of a crossover parameter of the boson mass.

• OSTI ID: 21250618
• Journal Information: Physical Review. D, Particles Fields, Vol. 78, Issue 3; Other Information: DOI: 10.1103/PhysRevD.78.034014; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
APPROXIMATIONS
BCS THEORY
BOSE-EINSTEIN CONDENSATION
BOSONS
COMPUTERIZED SIMULATION
CONDENSATES
CRITICAL TEMPERATURE
ELEMENTARY PARTICLES
FERMIONS
FLUCTUATIONS
INTERACTIONS
MASS
MEAN-FIELD THEORY
PHASE TRANSFORMATIONS
QUANTUM CHROMODYNAMICS
RELATIVISTIC RANGE
STATISTICAL MODELS
SUPERFLUIDITY
SYMMETRY
U-1 GROUPS