{
  "abstract": "Excitons provide a sensitive optical probe of electronic correlations in nearby two-dimensional materials, yet their coupling to intrinsic flat-band Mott systems remains largely unexplored. Here we combine gate-tunable optical spectroscopy with first-principles calculations to study monolayer WSe$_2$ in direct contact with the van der Waals Mott insulator Nb$_3$Cl$_8$. The gate evolution of WSe$_2$ excitonic resonances reveals signatures of a correlation-reconstructed Mott gap in Nb$_3$Cl$_8$ that is absent from the single-particle band picture. In the electron-doped regime, the WSe$_2$ 2s Rydberg exciton undergoes a multistage evolution and develops into interlayer attractive and repulsive polaron branches, showing that a Rydberg exciton can be dressed by strongly correlated flat-band electrons in an adjacent Mott layer. Under an out-of-plane magnetic field, spin-polarized Nb$_3$Cl$_8$ states further induce valley-selective exciton coupling, producing a strongly enhanced circular polarization of the WSe$_2$ exciton emission. These results extend exciton-based sensing and exciton-polaron physics to intrinsic flat-band Mott materials, providing an optical route to probe and engineer correlation-driven interfacial quasiparticles.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.07101",
  "author_total": 15,
  "authors": [
    {
      "name": "Xinyue Huang"
    },
    {
      "name": "Xintong Tan"
    },
    {
      "name": "Haowei Chen"
    },
    {
      "name": "Yingzhou Huang"
    },
    {
      "name": "Yushen Zhou"
    },
    {
      "name": "Yuchen Gao"
    },
    {
      "name": "Zhijie Ma"
    },
    {
      "name": "Chengxin Xiao"
    },
    {
      "name": "Kenji Watanabe"
    },
    {
      "name": "Takashi Taniguchi"
    },
    {
      "name": "Jianpeng Liu"
    },
    {
      "name": "Zuxin Chen"
    },
    {
      "name": "Youguo Shi"
    },
    {
      "name": "Wang Yao"
    },
    {
      "name": "Yu Ye"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/anmvcbnw73gwn.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.07101",
  "fulltext_url": null,
  "id": "anmvcbnw73gwn",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.07101",
  "language": null,
  "licence": "CC0-1.0",
  "licence_label": "CC0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/publicdomain/zero/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ],
    [
      "arxiv",
      "physics.optics"
    ],
    [
      "openalex",
      "2505|2D Materials and Applications"
    ]
  ],
  "openalex": "W7212083260",
  "pdf_url": "https://arxiv.org/pdf/2609.07101",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-07",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/anmvcbnw73gwn.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:48Z",
      "native_id": "2609.07101",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.07101"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.optics",
      "subfield": "optics-photonics"
    }
  ],
  "title": "Excitons probe intrinsic flat band Mottness in a van der Waals heterostructure",
  "title_text": "Excitons probe intrinsic flat band Mottness in a van der Waals heterostructure",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:48Z",
  "url": "https://research.draconitic.com/paper/anmvcbnw73gwn",
  "venue": "arXiv",
  "versions": []
}