{
  "abstract": "The sensitivity of an atomic spin sensor is fundamentally constrained by the quantum Fisher information (QFI) of the probe state. The pinched state, $|{F,0}\\rangle$, has an $(F+1)$-fold larger single-particle QFI for transverse-field sensing than the stretched state, $|{F,F}\\rangle$, corresponding to a predicted $\\sqrt{F+1}$ reduction in the spin-projection-noise-limited field uncertainty. We show that this advantage can be accessed in an rf sensing scheme by engineering a spectrum symmetric about $m=0$, yielding an ideal $(F+1)$-fold enhancement of magnetic-field response. For $^{87}\\mathrm{Rb}$ with $F=2$, we observe up to 2.7-fold response enhancement. Implementing this approach in a compact $0.8~\\mathrm{cm}^3$ anti-relaxation-coated multipass cell, we realize a single-beam, dual-axis, zero-field magnetometer, achieving $13$--$23$~$\\mathrm{fT}/\\sqrt{\\mathrm{Hz}}$ over $3$--$100$~Hz at room temperature.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.25714",
  "author_total": 4,
  "authors": [
    {
      "name": "Tingxuan Guo"
    },
    {
      "name": "Xiangyu Li"
    },
    {
      "name": "Yang Li"
    },
    {
      "name": "Kaifeng Zhao"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cy32ek2qcbp0f.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.25714",
  "fulltext_url": null,
  "id": "cy32ek2qcbp0f",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.25714",
  "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",
      "quant-ph"
    ],
    [
      "openalex",
      "3107|Atomic and Subatomic Physics Research"
    ]
  ],
  "openalex": "W7214124323",
  "pdf_url": "https://arxiv.org/pdf/2609.25714",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-22",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cy32ek2qcbp0f.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:39Z",
      "native_id": "2609.25714",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.25714"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Enhanced Atomic Magnetometry with a Pinched Spin State",
  "title_text": "Enhanced Atomic Magnetometry with a Pinched Spin State",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:39Z",
  "url": "https://research.draconitic.com/paper/cy32ek2qcbp0f",
  "venue": "arXiv",
  "versions": []
}