Effective interaction between molecules in the strong-coupling BEC regime of a superfluid fermi gas

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16 Citations (Scopus)

Abstract

We investigate the effective interaction between Cooper-pair molecules in the strong-coupling BEC regime of a superfluid Fermi gas with a Feshbach resonance. Our work uses a path integral formulation and a renormalization group (RG) analysis of fluctuations in a single-channel model. We show that a physical cutoff energy ωc originating from the finite molecular binding energy is the key to understanding the interaction between molecules in the BEC regime. Our work thus clari.es recent results by showing that a M = 2aF is a bare molecular scattering length while a M = (0.6-0.75)aF is the low-energy molecular scattering length renormalized to include high-energy scattering up to ωc (here, aF is the scattering length between Fermi atoms). We also include many-body effects at finite temperatures. We find that aM is strongly dependent on temperature, vanishing at Tc, consistent with the earlier Bose gas results of Bijlsma and Stoof.

Original languageEnglish
Pages (from-to)2659-2662
Number of pages4
JournalJournal of the Physical Society of Japan
Volume74
Issue number10
DOIs
Publication statusPublished - 2005 Oct 1
Externally publishedYes

Keywords

  • BCS-BEC crossover
  • Cold Fermi gas
  • Fermion superfluidity

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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