Gapless superconductivity from extremely dilute magnetic disorder in 2H-NbSe2−S
Most superconducting materials exhibit a vanishing density of states at the Fermi level and Anderson’s theorem posits that thesuperconducting gap is robust against nonmagnetic disorder. Although dilute magnetic impurities lead to localized in-gap states,these states typically have no bearing on the...
| Autores: | , , , , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.uam.es:10486/755540 |
| Acceso en línea: | https://hdl.handle.net/10486/755540 https://dx.doi.org/10.1002/adma.202519118 |
| Access Level: | acceso abierto |
| Palabra clave: | disorder gapless magnetic impurities STM superconductivity Yu–Shiba–Rusinovstates Física |
| Sumario: | Most superconducting materials exhibit a vanishing density of states at the Fermi level and Anderson’s theorem posits that thesuperconducting gap is robust against nonmagnetic disorder. Although dilute magnetic impurities lead to localized in-gap states,these states typically have no bearing on the material’s bulk superconducting properties. However, numerous experiments reveala finite density of states at the Fermi level in systems with an apparently negligible number of magnetic impurities. Here, usingscanning tunneling microscopy and self-consistent Bogoliubov-de Gennes calculations, we find that gapless superconductivityemerges in 2H-NbSe 2− S at remarkably low magnetic impurity concentrations. Furthermore, our density functional theorycalculations and in-gap quasiparticle interference measurements demonstrate that the Se-S substitution significantly modifies theband structure. This modification favours nesting and dictates the in-gap scattering for > 0, in stark contrast to the dominantcharge density wave interactions in pure 2H-NbSe 2. Our findings reveal an unusual superconducting response to disorder andhighlight the importance of incorporating material-specific band structures in the understanding of a superconductor’s responseto even very low concentrations of magnetic impurities |
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