{
  "abstract": "Turning a flat-band parent into an isolated Chern band requires supervise of destructive interference, hopping phases, and the cell translations of the bonds. We study this connection in a seven-orbital 2 times 2 supercell honeycomb-vacancy lattice, combining analytic reductions with Bloch spectra, lattice Chern invariants, and quantum geometry. The parent lattice has three exact flat branches, a smooth periodic zero mode, and a compact localized state. A uniform gap bound shows that faint intracell-loop hopping preserves two topologically trivial insulating gaps. The intracell hopping graph also admits a staggered chiral coloring: reversing site amplitudes according to this coloring links opposite energies at momenta separated by half a reciprocal period. This constraint restricts the isolated central band to even Chern numbers and forbids a zero-energy insulating filling at every loop phase. Purely imaginary loop hopping admits a real gauge, whereas other phases allow paired band contacts connecting central bands with C3=2 and C3=4. On a specified strong-loop cut, third-order masses open the direct gaps; these gaps shrink faster than the bandwidth as the coupling grows. Changing the bond connectivity to an oriented honeycomb next-nearest-neighbor extension generates a narrower Chern band with nonuniform quantum geometry. These results distinguish individual-band topology from occupied-group topology and reveal how bond connectivity and cell translations determine which topological bands can emerge from an exactly flat parent.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.36738",
  "author_total": 5,
  "authors": [
    {
      "name": "Weizhuo Xu"
    },
    {
      "name": "Jiachen Qian"
    },
    {
      "name": "Shuaihua Zhang"
    },
    {
      "name": "Yanling Wu"
    },
    {
      "name": "Jun Li"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fvb4mkqe4sgqq.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.36738",
  "fulltext_url": null,
  "id": "fvb4mkqe4sgqq",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.36738",
  "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"
    ],
    [
      "openalex",
      "3107|Topological Materials and Phenomena"
    ]
  ],
  "openalex": "W7224124300",
  "pdf_url": "https://arxiv.org/pdf/2610.36738",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fvb4mkqe4sgqq.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:50Z",
      "native_id": "2610.36738",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.36738"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mes-hall",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Algebraic flat bands and even central-band Chern numbers in a seven-orbital hopping model",
  "title_text": "Algebraic flat bands and even central-band Chern numbers in a seven-orbital hopping model",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:50Z",
  "url": "https://research.draconitic.com/paper/fvb4mkqe4sgqq",
  "venue": "arXiv",
  "versions": []
}