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Equation of state of a Fermi gas in the BEC-BCS crossover: a quantum Monte Carlo study

G. E. Astrakharchik·J. Boronat·J. Casulleras·S. Giorgini
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Abstract

We calculate the equation of state of a two-component Fermi gas with attractive short-range interspecies interactions using the fixed-node diffusion Monte Carlo method. The interaction strength is varied over a wide range by tuning the value $a$ of the s-wave scattering length of the two-body potential. For $a>0$ and $a$ smaller than the inverse Fermi wavevector our results show a molecular regime with repulsive interactions well described by the dimer-dimer scattering length $a_m=0.6 a$. The pair correlation functions of parallel and opposite spins are also discussed as a function of the interaction strength.

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G. E. Astrakharchik, J. Boronat, J. Casulleras, S. Giorgini. 2004-10-12. Equation of state of a Fermi gas in the BEC-BCS crossover: a quantum Monte Carlo study. https://doi.org/10.1103/physrevlett.93.200404

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