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arXiv · 2603.11986

Phase stiffness in flat-band superconductors with nodal pairing

A. A. Zyuzin·A. Yu. Zyuzin
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Abstract

We study Bogoliubov quasiparticle spectrum in a two-band system with momentum-dependent hybridization between a dispersive band and a flat band. The interplay between the interband mixing and intraband Cooper pairing may give rise to a parabolic node in the spectrum of flat band quasiparticles, resulting in a quadratic temperature dependence of the superconducting phase stiffness at low temperatures. We also comment that nonmagnetic disorder induces Machida-Shibata deep subgap resonances suggesting the sensitivity of flat-band superconductivity to disorder.

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A. A. Zyuzin, A. Yu. Zyuzin. 2026-03-12. Phase stiffness in flat-band superconductors with nodal pairing. https://arxiv.org/abs/2603.11986

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