Beyond mean-field corrections to the quasiparticle spectrum of superfluid Fermi gases

Abstract

We investigate the fermionic quasiparticle branch of superfluid Fermi gases in the BCS-BEC crossover and calculate the quasiparticle lifetime and energy shift due to its coupling with the collective mode. The only close-to-resonance process that low-energy quasiparticles can undergo at zero temperature is the emission of a bosonic excitation from the phononic branch. Close to the minimum of the branch we find that the quasiparticles remain undamped, allowing us to compute corrections to experimentally relevant quantities such as the energy gap, location of the minimum, effective mass, and Landau critical velocity.

arXiv comment6 pages, 3 figures

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Cited by in corpus (4)

• One-dimensional scattering of two-dimensional fermions near quantum criticality
• Linear response of a superfluid Fermi gas inside its pair-breaking continuum
• Quasiparticle disintegration in fermionic superfluids
• Pair-Condensation Peak in Radio-Frequency Dimer-Projection Spectroscopy of a Unitary Fermi Gas