Inhomogeneity, Fluctuations, and Gap Filling in Overdoped Cuprates

Fuente: arXiv
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Main Authors: Sulangi, Miguel Antonio, Farmilo, Willem, Kreisel, Andreas, Pal, Mainak, Atkinson, W. A., Hirschfeld, P. J.
Format: Preprint
Published: 2025
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_version_ 1866911281724784640
author Sulangi, Miguel Antonio
Farmilo, Willem
Kreisel, Andreas
Pal, Mainak
Atkinson, W. A.
Hirschfeld, P. J.
author_facet Sulangi, Miguel Antonio
Farmilo, Willem
Kreisel, Andreas
Pal, Mainak
Atkinson, W. A.
Hirschfeld, P. J.
contents Several recent experiments have challenged the premise that cuprate high-temperature superconductors approach conventional Landau-BCS behavior in the high-doping limit. We argue, based on an analysis of their superconducting spectra, that anomalous properties seen in the most-studied overdoped cuprates require a pairing interaction that is strongly inhomogeneous on nm length scales. This is consistent with recent proposals that the "strange-metal" phase above $T_c$ in the same doping range arises from a spatially random interaction. We show, via mean-field Bogoliubov-de Gennes (BdG) calculations and time-dependent Ginzburg-Landau (TDGL) simulations, that key features of the observed tunneling spectra are reproduced when both inhomogeneity and thermal phase fluctuations are accounted for. In accord with experiments, BdG calculations find that low-$T$ spectra are highly inhomogeneous and exhibit a low-energy spectral shoulder and broad coherence peaks. However, the spectral gap in this approach becomes homogeneous at high $T$, in contrast to experiments. This is resolved when thermal fluctuations are included; in this case, global phase coherence is lost at the superconducting $T_c$ via a broadened BKT transition, while robust phase-coherent superconducting islands persist well above $T_c$. The local spectrum remains inhomogeneous at $T_c$, and the gap is found to fill instead of close with increasing temperature.
format Preprint
id arxiv_https___arxiv_org_abs_2503_20861
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Inhomogeneity, Fluctuations, and Gap Filling in Overdoped Cuprates
Sulangi, Miguel Antonio
Farmilo, Willem
Kreisel, Andreas
Pal, Mainak
Atkinson, W. A.
Hirschfeld, P. J.
Superconductivity
Strongly Correlated Electrons
Several recent experiments have challenged the premise that cuprate high-temperature superconductors approach conventional Landau-BCS behavior in the high-doping limit. We argue, based on an analysis of their superconducting spectra, that anomalous properties seen in the most-studied overdoped cuprates require a pairing interaction that is strongly inhomogeneous on nm length scales. This is consistent with recent proposals that the "strange-metal" phase above $T_c$ in the same doping range arises from a spatially random interaction. We show, via mean-field Bogoliubov-de Gennes (BdG) calculations and time-dependent Ginzburg-Landau (TDGL) simulations, that key features of the observed tunneling spectra are reproduced when both inhomogeneity and thermal phase fluctuations are accounted for. In accord with experiments, BdG calculations find that low-$T$ spectra are highly inhomogeneous and exhibit a low-energy spectral shoulder and broad coherence peaks. However, the spectral gap in this approach becomes homogeneous at high $T$, in contrast to experiments. This is resolved when thermal fluctuations are included; in this case, global phase coherence is lost at the superconducting $T_c$ via a broadened BKT transition, while robust phase-coherent superconducting islands persist well above $T_c$. The local spectrum remains inhomogeneous at $T_c$, and the gap is found to fill instead of close with increasing temperature.
title Inhomogeneity, Fluctuations, and Gap Filling in Overdoped Cuprates
topic Superconductivity
Strongly Correlated Electrons
url https://arxiv.org/abs/2503.20861