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arXiv · 2306.02127

Finite-range effect in the two-dimensional density-induced BCS-BEC crossover

Hikaru Sakakibara·Hiroyuki Tajima·Haozhao Liang
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Abstract

We theoretically investigate the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensation (BEC) crossover in a two-dimensional Fermi gas with the finite-range interaction by using the Hartree-Fock-Bogoliubov theory. Expanding the scattering phase shift in terms of the scattering length and effective range, we discuss the effect of the finite-range interaction on the pairing and thermodynamic properties. By solving the gap equation and the number equation self-consistently, we numerically calculate the effective-range dependence of the pairing gap, chemical potential, and pair size throughout the BCS-BEC crossover. Our results would be useful for further understanding of low-dimensional many-body problems.

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Hikaru Sakakibara, Hiroyuki Tajima, Haozhao Liang. 2023-06-03. Finite-range effect in the two-dimensional density-induced BCS-BEC crossover. https://doi.org/10.1093/ptep%2Fptad098

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