Medium effects close to s- and p-wave Feshbach resonances in atomic Fermi gases

Renyuan Liao; Khandker F. Quader

doi:10.1103/physreva.86.012704

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arXiv · 1207.2856

Medium effects close to s- and p-wave Feshbach resonances in atomic Fermi gases

Renyuan Liao·Khandker F. Quader

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Abstract

Many-body effects may influence properties, such as scattering parameters, nature of pairing, etc., close to a Feshbach resonance in the fermion BEC-BCS crossover problem. We study effects such as these using a tractable crossing-symmetric approach. This method allow us to include quantum fluctuations, such as, density, current, spin, spin-current and the higher-order fluctuations in a self-consistent fashion. The underlying fermion interaction is reflected in the "driving" term. We perform calculations here on both Bose-Einstein condensate (BEC) and BCS sides, and taking the driving term to be finite range, and of arbitrary strength. These are related to two-body singlet and triplet scattering parameters, and can be connected with experimental s- and p-wave Feshbach resonances. We include the $\ell=0$ density and spin fluctuations, as well as $\ell=1$ current and spin-current fluctuations. We calculate renormalized scattering amplitudes, pairing amplitudes, nature of pairing, etc., on both the BEC and BCS sides. We then compare our results qualitatively with experiments.

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Renyuan Liao, Khandker F. Quader. 2012-07-12. Medium effects close to s- and p-wave Feshbach resonances in atomic Fermi gases. https://doi.org/10.1103/physreva.86.012704

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