{
  "abstract": "Nitrogen-vacancy (NV) centers in diamond exist in neutral (NV0) and negatively charged (NV-) states, and quantifying their respective photoluminescence (PL) contributions is important for charge-state-based measurements. Existing methods either require additional experimental control or may suffer from limited physical identifiability. Here, we introduce a geometric method for determining NV charge-state contributions from PL spectra acquired at different excitation intensities. Each spectrum is mapped into a low-dimensional space through broadband spectral weighting, where changes in the relative NV0 and NV- contributions trace a one-dimensional trajectory. Zero-phonon-line (ZPL) information from two spectra physically calibrates this trajectory, enabling the NV-PL contribution to be determined by geometric projection. Measurements on two bulk single-crystal diamond samples yielded NV- contributions in close agreement with those obtained using an independent dual-excitation reference-spectrum method, with root-mean-square errors of 1.11 and 0.31 percentage points. Under additive spectral noise, the proposed method exhibited more than an order of magnitude less variation than a ZPL-only method. Fisher-information analysis further showed that the three-dimensional CIE XYZ representation retained approximately 81% of the information about the NV- contribution available in the full spectrum. These results establish a physically calibrated approach to low-dimensional spectral estimation that combines reduced experimental overhead with robust parameter estimation and provides a general framework for spectral sensing governed by a small number of physical degrees of freedom.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.38739",
  "author_total": 3,
  "authors": [
    {
      "name": "Yuto Yamakawa"
    },
    {
      "name": "Keisuke Oshimi"
    },
    {
      "name": "Keigo Arai"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/33zgf598m9hqj.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.38739",
  "fulltext_url": null,
  "id": "33zgf598m9hqj",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.38739",
  "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",
      "2505|Diamond and Carbon-based Materials Research"
    ]
  ],
  "openalex": "W7215111769",
  "pdf_url": "https://arxiv.org/pdf/2609.38739",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/33zgf598m9hqj.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:49Z",
      "native_id": "2609.38739",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.38739"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Geometric estimation of NV charge-state contributions from a low-dimensional spectral representation",
  "title_text": "Geometric estimation of NV charge-state contributions from a low-dimensional spectral representation",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:49Z",
  "url": "https://research.draconitic.com/paper/33zgf598m9hqj",
  "venue": "arXiv",
  "versions": []
}