Superconducting pairing from repulsive interactions of fermions in a flat-band system

Abstract

Fermion systems with flat bands can boost superconductivity by enhancing the density of states at the Fermi level. We use quasiexact numerical methods to show that repulsive interactions between spinless fermions in a one-dimensional (1D) flat-band system, the Creutz ladder, give a finite pairing energy that increases with repulsion, though charge quasi-order (QO) remains dominant. Adding an attractive component shifts the balance in favor of superconductivity and the interplay of two flat bands further yields a remarkable enhancement of superconductivity, well outside of known paradigms for 1D fermions.

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Cited by in corpus (5)

• Majorana corner states on the dice lattice
• Flat Bands and Compact Localised States: A Carrollian roadmap
• Superconductivity and pair density waves from nearest-neighbor interactions in frustrated lattice geometries
• Symmetry-enforced double Weyl points, multiband quantum geometry, and singular flat bands of doping-induced states at the Fermi level
• Phase diagram of a coupled trimer system at half filling using the Hubbard model