BEC-BCS Crossover with Feshbach Resonance for a Three-Hyperfine-Species Model

Abstract

We consider the behavior of an ultracold Fermi gas across a narrow Feshbach resonance, where the occupation of the closed channel may not be negligible. While the corrections to the single-channel formulae associated with the nonzero chemical potential and with particle conservation have been considered in the existing literature, there is a further effect, namely the "inter-channel Pauli exclusion principle" associated with the fact that a single hyperfine species may be common to the two channels. We focus on this effect and show that, as intuitively expected, the resulting corrections are of order $E_F/\eta$, where $E_F$ is the Fermi energy of the gas in the absence of interactions and $\eta$ is the Zeeman energy difference between the two channels. We also consider the related corrections to the fermionic excitation spectrum, and briefly discuss the collective modes of the system.

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• Weakly bound dimers of fermionic atoms
• Resonantly-paired fermionic superfluids
• Universal Properties of the Ultra-Cold Fermi Gas
• An exactly solvable model of the BCS-BEC crossover
• Multi-channel scattering and Feshbach resonances: Effective theory, phenomenology, and many-body effects
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• BEC-BCS Crossover with Feshbach Resonance for Three-Hyperfine-Species Model

Cited by in corpus (1)

• Two-band description of resonant superfluidity in atomic Fermi gases