{
  "abstract": "We find a dip in the optimized rotation quantum Fisher information of a zero-magnetization ferromagnetic spin-1 Bose-Einstein condensate near the excited-state quantum phase transition. Its displacement from $ε_c=-q$ decreases on an inverse-size scale. At $q=0.6,0.8,1.0,1.2$, the dip value of $F_{\\max}$ equals $2\\langle S^2\\rangle$ for $N$ up to $3840$, linking it to total-spin fluctuations. A semiclassical orbit average normalized by the classical density of states describes the dip over $N=120$--$3840$ with maximum relative residual below $0.028$; a small power law fits comparably. Inserting the measured energy offsets directly into the semiclassical formula leaves residuals of $17$--$30\\%$, so $κ$ acts as an effective cutoff. Among retained states, spin-nematic squeezing occurs at the spectral edges. Separately, fixed-index excited-state sweeps have half-excitation times between $11.2$ and $13.1$ times their ground-state counterparts, with local size exponents increasing across the four sizes.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.28163",
  "author_total": 3,
  "authors": [
    {
      "name": "Yi Ding"
    },
    {
      "name": "Junyan Luo"
    },
    {
      "name": "Yixiao Huang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3e3hh00yz7p2q.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.28163",
  "fulltext_url": null,
  "id": "3e3hh00yz7p2q",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.28163",
  "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.quant-gas"
    ],
    [
      "openalex",
      "3107|Cold Atom Physics and Bose-Einstein Condensates"
    ]
  ],
  "openalex": "W7223133508",
  "pdf_url": "https://arxiv.org/pdf/2610.28163",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3e3hh00yz7p2q.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:04Z",
      "native_id": "2610.28163",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.28163"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.quant-gas",
      "subfield": "amo"
    },
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.quant-gas",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Finite-size spin fluctuations and fixed-index sweeps in a ferromagnetic spinor condensate",
  "title_text": "Finite-size spin fluctuations and fixed-index sweeps in a ferromagnetic spinor condensate",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:04Z",
  "url": "https://research.draconitic.com/paper/3e3hh00yz7p2q",
  "venue": "arXiv",
  "versions": []
}