{
  "abstract": "The emergence of high-$T_c$ superconductivity in pressurized La$_3$Ni$_2$O$_7$ is intimately linked to a structural transition that suppresses the tilts of the NiO$_6$ octahedra, yet its impact on the electronic structure remains poorly understood. Here, we probe the electronic response across this tilt-free transition at $T_{st}\\simeq 544$ K using broadband infrared-to-visible reflectivity at ambient pressure, covering photon energies from 15 meV to 3.2 eV. We observe a pronounced redistribution of spectral weight over an exceptionally broad energy range, with spectral weight transferred from excitations between 1 and 3 eV toward low-energy excitations below 1 eV. Most strikingly, two low-energy interband excitations progressively converge and merge upon entering the tilt-free phase, revealing a substantial reconstruction of the finite-energy electronic structure. These changes point to a reconstruction of the bilayer Ni $3d_{z^2}$-derived electronic states, whose interlayer coupling is central to proposed mechanisms of superconductivity in La$_3$Ni$_2$O$_7$. Our results establish the tilt-free transition as a direct route to reorganizing the electronic degrees of freedom implicated in high-$T_c$ superconductivity and provide an ambient-pressure reference for the electronic structure of the superconducting state.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.40139",
  "author_total": 8,
  "authors": [
    {
      "name": "Mengjie Kong"
    },
    {
      "name": "Gergely Németh"
    },
    {
      "name": "Yingpeng Yu"
    },
    {
      "name": "Bosen Wang"
    },
    {
      "name": "Jianping Sun"
    },
    {
      "name": "Jinguang Cheng"
    },
    {
      "name": "Ferenc Borondics"
    },
    {
      "name": "Bastien Michon"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ft0zyg34vbqfw.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.40139",
  "fulltext_url": null,
  "id": "ft0zyg34vbqfw",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.40139",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.supr-con"
    ],
    [
      "openalex",
      "3104|Physics of Superconductivity and Magnetism"
    ]
  ],
  "openalex": "W7215038112",
  "pdf_url": "https://arxiv.org/pdf/2609.40139",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ft0zyg34vbqfw.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:49Z",
      "native_id": "2609.40139",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.40139"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.supr-con",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Electronic Reconstruction across the Tilt-Free Transition in La$_3$Ni$_2$O$_7$",
  "title_text": "Electronic Reconstruction across the Tilt-Free Transition in La_3Ni_2O_7",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:49Z",
  "url": "https://research.draconitic.com/paper/ft0zyg34vbqfw",
  "venue": "arXiv",
  "versions": []
}