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arXiv · 2610.20434

Universal enhancement of the pairing gap in a dilute Fermi superfluid

Silas R. Beane·Roland C. Farrell·Cameron P. Shotwell
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Abstract

At zero temperature, a dilute Fermi gas with an attractive contact interaction forms a superfluid with gapped fermionic excitations. We show that the gap at weak coupling can be organized as a trans-series expansion in the interaction strength and the asymptotic Gor'kov-Melik-Barkhudarov gap. Low-energy virtual quasiparticles generate corrections that are linear in the gap with a leading coefficient nearly 25$\times$ larger than the other known coefficients. This substantially increases the gap at intermediate densities, highlighting that systematic corrections are crucial for quantitative predictions.

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Silas R. Beane, Roland C. Farrell, Cameron P. Shotwell. 2026-10-14. Universal enhancement of the pairing gap in a dilute Fermi superfluid. https://arxiv.org/abs/2610.20434

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