{
  "abstract": "Excitons are conventionally expected to destabilize at high photoexcitation densities, as screening weakens the electron-hole attraction. Recent studies, however, challenge this paradigm, suggesting that excitons generated by strong optical pumping can remain stable even beyond the onset of population inversion. Here, using time- and angle-resolved photoelectron spectroscopy on 2D hybrid perovskites, we provide direct evidence for such a high-density excitonic state, characterized by a distinctive Mexican-hat dispersion. Remarkably, this excitonic band reconstruction endures for orders of magnitude longer than the optical coherence time, revealing a population-sustained electronic structure that survives well into the incoherent regime. The excitonic resonance also persists far beyond optical saturation, at densities where exciton wavefunctions strongly overlap. Our findings reveal a long-lived, high-density quantum fluid of excitons with characteristics reminiscent of a BCS condensate, an electronic structure markedly different from that of the dilute limit.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.32437",
  "author_total": 15,
  "authors": [
    {
      "name": "Weiyan Qi"
    },
    {
      "name": "Stefano Ponzoni"
    },
    {
      "name": "Ashim Pramanik"
    },
    {
      "name": "Vitaly Gorelov"
    },
    {
      "name": "Yannis Laplace"
    },
    {
      "name": "Gianluca Stefanucci"
    },
    {
      "name": "Enrico Perfetto"
    },
    {
      "name": "Esteban Morcos"
    },
    {
      "name": "Marino Marsi"
    },
    {
      "name": "Steven Francis Udaundo"
    },
    {
      "name": "Sebastian Maherlein"
    },
    {
      "name": "Amina Taleb-Ibrahimi"
    },
    {
      "name": "Kaibo Zheng"
    },
    {
      "name": "Tonu Pullerits"
    },
    {
      "name": "Luca Perfetti"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/94tz6x18y389x.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.32437",
  "fulltext_url": null,
  "id": "94tz6x18y389x",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.32437",
  "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.other"
    ],
    [
      "openalex",
      "3107|Strong Light-Matter Interactions"
    ]
  ],
  "openalex": "W7223679613",
  "pdf_url": "https://arxiv.org/pdf/2610.32437",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/94tz6x18y389x.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:15Z",
      "native_id": "2610.32437",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.32437"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.other",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Electronic structure of a persistent excitonic fluid far beyond the Mott limit",
  "title_text": "Electronic structure of a persistent excitonic fluid far beyond the Mott limit",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:15Z",
  "url": "https://research.draconitic.com/paper/94tz6x18y389x",
  "venue": "arXiv",
  "versions": []
}