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arXiv · 2607.29620

Pairing near the boundary of a box-shaped trap in the BEC-BCS crossover

Kelly R. Patton·Daniel E. Sheehy
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Abstract

We study pairing of attractively interacting fermions confined to a box-shaped trap. In contrast to the infinite translationally-invariant case, where the local pairing order is spatially uniform and undergoes the Bose-Einstein Condensate to Bardeen-Cooper-Schrieffer (BEC-BCS) crossover as interactions are varied, in this case the local pairing is expected to vary rapidly near the edge of the box. We address this problem in the limit of a semi-infinite superfluid, finding that the nature of the edge pairing depends sensitively on the coupling. The local pairing exhibits Friedel-like oscillations in the weak coupling BCS regime that are suppressed with increasing coupling strength towards the BEC regime.

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Kelly R. Patton, Daniel E. Sheehy. 2026-07-31. Pairing near the boundary of a box-shaped trap in the BEC-BCS crossover. https://arxiv.org/abs/2607.29620

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