2007/12/31 by Jisheng Chen, Ji-sheng Chen, Jiarong Li +4 · 1 citation
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Cold Atom Physics and Bose-Einstein Condensates #Quantum, superfluid, helium dynamics #cond-mat.quant-gas #cond-mat.stat-mech #hep-ph #nucl-th #quant-ph
paper · pdf · doi:10.1088/1742-5468/2008/12/p12008
published as J. Stat. Mech. 12 (2008) P12008 · Final published version revised according to comments; with more figures
arxiv created 2008/12/15 · openalex publication_date 2008/12/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
We study the roles of the dynamical high order perturbation and statistically non-linear infrared fluctuation/correlation in the virial equation of state for the Fermi gas in the unitary limit. Incorporating the quantum level crossing rearrangement effects, the spontaneously generated entropy departing from the mean-field theory formalism leads to concise thermodynamical expressions. The dimensionless virial coefficients with complex non-local correlations are calculated up to the fourth order for the first time. The virial coefficients of unitary Fermi gas are found to be proportional to those of the ideal quantum gas with integer ratios through a general term formula. Counterintuitively, contrary to those of the ideal bosons ( ) or fermions ( ), the second virial coefficient a 2 of Fermi gas at unitarity is found to be equal to zero. With the vanishing leading order quantum correction, the BCS–BEC crossover thermodynamics manifests the famous pure classical Boyle's law in the Boltzmann regime. The non-Gaussian correlation phenomena can be validated by studying the Joule–Thomson effect.