{
  "abstract": "Kagome FeSn exhibits an occupied flat band at its terminated surface, whereas bulk FeSn adopts A-type antiferromagnetic order and does not display the same feature. Here, we combine density functional theory with primitive- and doubled-cell analysis and a double-layer tight-binding model to determine how interlayer electronic coupling and magnetic stacking control flat-band formation in FeSn. We identify an occupied Fe-$d_{z^2}$-derived flat-band manifold in the ferromagnetic state that is consistent with the experimentally observed surface feature. Brillouin-zone folding reveals that its flat branch originates from the $k_z=\\fracπ{c}$ sector of the primitive cell, demonstrating that it cannot be understood as an isolated kagome-layer state. Instead, the state depends on coupling between neighboring kagome layers and can be seen as a result of antibonding coupling between nearest neighbor kagome layers. A double-layer tight-binding analysis identifies interlayer Fe-Fe hopping as the dominant microscopic coupling responsible for this behavior, while a contrasting unoccupied flat-band-related manifold is governed primarily by intralayer Fe-Sn hybridization. These results establish interlayer coupling and magnetic stacking as key control parameters for kagome flat bands and highlight how coupling between layers can generate and tune extended correlated-electron states in quantum materials.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.28968",
  "author_total": 4,
  "authors": [
    {
      "name": "Shimin Zhang"
    },
    {
      "name": "Bipasa Samanta"
    },
    {
      "name": "Ho Viet Thang"
    },
    {
      "name": "Alexandru B. Georgescu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6gn18chew19we.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.28968",
  "fulltext_url": null,
  "id": "6gn18chew19we",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.28968",
  "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.mtrl-sci"
    ],
    [
      "arxiv",
      "cond-mat.str-el"
    ],
    [
      "openalex",
      "3104|Advanced Condensed Matter Physics"
    ]
  ],
  "openalex": "W7214330991",
  "pdf_url": "https://arxiv.org/pdf/2609.28968",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-24",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6gn18chew19we.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:24:11Z",
      "native_id": "2609.28968",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.28968"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Beyond the Kagome Layer: Interlayer Origin of the Flat Band in FeSn",
  "title_text": "Beyond the Kagome Layer: Interlayer Origin of the Flat Band in FeSn",
  "type": "preprint",
  "updated_at": "2026-10-30T12:24:11Z",
  "url": "https://research.draconitic.com/paper/6gn18chew19we",
  "venue": "arXiv",
  "versions": []
}