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DOE OSTI · 2565207

Universal corrections to the superfluid gap in a cold Fermi gas

Beane, Silas R. [Universität Bern (Switzerland); University of Washington, Seattle, WA (United States); University of Washington] (ORCID:0000000184634948)·Capatti, Zeno [Universität Bern (Switzerland)] (ORCID:0000000186934258)·Farrell, Roland C. [Universität Bern (Switzerland); University of Washington, Seattle, WA (United States)] (ORCID:0000000171890424)
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Abstract

A framework for computing the superfluid gap in an effective field theory (EFT) of fermions interacting via momentum-independent contact forces is developed. The leading universal corrections in the EFT are one-loop in-medium effects at the Fermi surface, and reproduce the well-known Gor'kov-Melik-Barkhudarov result. Here, the complete subleading universal corrections are presented here, and include one-loop effects away from the Fermi surface, two-loop in-medium effects, as well as modifications to the fermion propagator. Together, these effects are found to reduce the gap at low densities. Applications to neutron superfluidity in neutron stars are also discussed.

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73 NUCLEAR PHYSICS AND RADIATION PHYSICSEffective field theoryFermi gasSuperfluidsUltracold gasesUniversality

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Beane, Silas R. [Universität Bern (Switzerland); University of Washington, Seattle, WA (United States); University of Washington] (ORCID:0000000184634948), Capatti, Zeno [Universität Bern (Switzerland)] (ORCID:0000000186934258), Farrell, Roland C. [Universität Bern (Switzerland); University of Washington, Seattle, WA (United States)] (ORCID:0000000171890424). 2025-01-13. Universal corrections to the superfluid gap in a cold Fermi gas. https://doi.org/10.1103/physreva.111.013309

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