{
  "abstract": "Nitrogen-vacancy (NV) centre ensembles are leading room-temperature magnetometers, but their sensitivity is usually extracted from a single resonance and relies on external microwave and bias-field hardware. This work proposes a chip-scale NV magnetometer built around a one-dimensional YIG/CoFeB magnonic crystal, in which a single structural defect forms a passive magnonic cavity and integrated permanent magnets supply the bias field. Micromagnetic simulations show a defect-localised spin-wave mode at 2.910 GHz inside the 2.5-3.0 GHz magnonic band gap, 40 MHz from the NV zero-field splitting, with a band structure that matches an independent plane-wave calculation. A Tavis-Cummings/Lindblad model in which the microwave reaches the NV ensemble through this mode predicts a hyperfine-resolved optically detected magnetic resonance spectrum that is strong only within the mode linewidth, and a dispersive homodyne response with one steep edge per $^{14}$N hyperfine line. The master-equation solutions agree with the closed-form homodyne steady state ($R^2 > 0.9999$) and with an approximate analytic ODMR theory (peak positions within 0.012 MHz). For a critically coupled readout with room-temperature electronics, combining the three edges gives a projected sensitivity of 93 pT/$\\sqrt{\\rm Hz}$, a $\\sqrt{3}$-fold gain over the best single edge. Mapping the sensitivity against the NV-magnon coupling reveals an optimum near $g_{\\rm ens}/2π\\approx 0.2$-$0.4$ MHz, where it reaches 72 pT/$\\sqrt{\\rm Hz}$ for a 0.64 MHz spin linewidth and 19 pT/$\\sqrt{\\rm Hz}$ for 0.17 MHz, with thermal limits of 6.6 and 1.7 pT/$\\sqrt{\\rm Hz}$. The antenna-mode coupling, the NV-magnon coupling and the spin linewidth are therefore the main design levers.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.11350",
  "author_total": 1,
  "authors": [
    {
      "name": "Nikhil Kumar"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/d3wcxem9hg0f6.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.11350",
  "fulltext_url": null,
  "id": "d3wcxem9hg0f6",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.11350",
  "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.mes-hall"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "2505|Diamond and Carbon-based Materials Research"
    ]
  ],
  "openalex": "W7221098287",
  "pdf_url": "https://arxiv.org/pdf/2610.11350",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/d3wcxem9hg0f6.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:54Z",
      "native_id": "2610.11350",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.11350"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mes-hall",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Magnonic cavity-enhanced quantum magnetometry with nitrogen-vacancy centre ensembles",
  "title_text": "Magnonic cavity-enhanced quantum magnetometry with nitrogen-vacancy centre ensembles",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:54Z",
  "url": "https://research.draconitic.com/paper/d3wcxem9hg0f6",
  "venue": "arXiv",
  "versions": []
}