{
  "abstract": "Exciton condensates are long-sought correlated quantum states arising from macroscopic coherence of bound electron-hole pairs. Although equilibrium and transient excitonic states have been reported in several material platforms, direct evidence for a light-induced exciton condensate state has been challenging to achieve as an intrinsic property of a bulk quantum material. Here, we use time- and angle-resolved photoemission spectroscopy to investigate long-lived photoexcited carriers in the intrinsic magnetic topological insulator MnBi$_2$Te$_4$ with the chemical potential tuned to the topological surface state by Sb substitution. Following optical excitation, we observe the delayed emergence of a transient state whose formation coincides with depopulation of the bulk conduction band and whose lifetime extends to the microsecond timescale. The quasiparticle dispersion exhibits a pronounced flattening and develops a Mexican-hat-like profile. These spectral signatures are consistent with the formation of a metastable excitonic condensate state. Our results establish magnetic topological insulators as a promising platform for investigating long-lived photoinduced many-body states and their interplay with topology and magnetism.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.27079",
  "author_total": 10,
  "authors": [
    {
      "name": "Paulina Majchrzak"
    },
    {
      "name": "Chakradhar Sahoo"
    },
    {
      "name": "Manuel Tuniz"
    },
    {
      "name": "Wibke Bronsch"
    },
    {
      "name": "Denny Puntel"
    },
    {
      "name": "Federico Cilento"
    },
    {
      "name": "Xing-Chen Pan"
    },
    {
      "name": "Jakob Kjærulff Svaneborg"
    },
    {
      "name": "Yong P. Chen"
    },
    {
      "name": "Søren Ulstrup"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4z60fkrq0j21v.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.27079",
  "fulltext_url": null,
  "id": "4z60fkrq0j21v",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.27079",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mes-hall"
    ],
    [
      "arxiv",
      "cond-mat.str-el"
    ],
    [
      "openalex",
      "3107|Topological Materials and Phenomena"
    ]
  ],
  "openalex": "W7214201291",
  "pdf_url": "https://arxiv.org/pdf/2609.27079",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-22",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4z60fkrq0j21v.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:56Z",
      "native_id": "2609.27079",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.27079"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mes-hall",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Spectroscopic signatures of persistent exciton condensation in a bulk magnetic topological insulator",
  "title_text": "Spectroscopic signatures of persistent exciton condensation in a bulk magnetic topological insulator",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:56Z",
  "url": "https://research.draconitic.com/paper/4z60fkrq0j21v",
  "venue": "arXiv",
  "versions": []
}