{
  "abstract": "We developed a highly sensitive and long-term stable diamond quantum magnetometer by integrating a dual-feedback system that compensates for common- and differential-mode frequency shifts in double-quantum (DQ) 4-Ramsey interferometry. Detecting extremely weak magnetic-field signals requires extensive signal accumulation to enhance the signal-to-noise ratio. However, deviations from the optimal operating frequencies caused by thermal drift or environmental magnetic noise severely hinder the long-term stability of such a sensing system. To overcome the limitation, we first derived analytical solutions for the signal response to common- and differential-mode detunings based on a detuning-inclusive Hamiltonian to theoretically clarify the robustness limit in DQ 4-Ramsey sensing. Guided by this theoretical model, we introduced synchronized frequency modulation and a dual-feedback scheme to independently track and compensate for these frequency shifts while maintaining an optimal magnetic-field response. The proposed method enabled stable continuous operation against temperature variations of 2.8 K. By maintaining a magnetic field sensitivity of 7.0 pT/Hz^1/2 in the frequency range of 5-100 Hz for a prolonged duration of 4 hours, we achieved an extremely low noise floor of 64 fT/Hz^1/2. During prolonged continuous sensing, the system exhibited the expected 1/T^1/2 scaling with integration time T, and prevented both the underestimation of amplitude and waveform distortion. These results establish a robust approach for long-term DQ 4-Ramsey diamond magnetometry and demonstrate its potential for detecting weak biomagnetic signals.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.05907",
  "author_total": 14,
  "authors": [
    {
      "name": "Yuta Araki"
    },
    {
      "name": "Takeharu Sekiguchi"
    },
    {
      "name": "Yuji Hatano"
    },
    {
      "name": "Naota Sekiguchi"
    },
    {
      "name": "Zehan Li"
    },
    {
      "name": "Chikara Shinei"
    },
    {
      "name": "Masashi Miyakawa"
    },
    {
      "name": "Takashi Taniguchi"
    },
    {
      "name": "Tokuyuki Teraji"
    },
    {
      "name": "Hiroshi Abe"
    },
    {
      "name": "Shinobu Onoda"
    },
    {
      "name": "Takeshi Ohshima"
    },
    {
      "name": "Mutsuko Hatano"
    },
    {
      "name": "Takayuki Iwasaki"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3vx902v20chre.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.05907",
  "fulltext_url": null,
  "id": "3vx902v20chre",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.05907",
  "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": "W7220676628",
  "pdf_url": "https://arxiv.org/pdf/2610.05907",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3vx902v20chre.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:01Z",
      "native_id": "2610.05907",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.05907"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Robust Diamond Quantum Sensing in Double-Quantum 4-Ramsey Interferometry by Dual-Feedback Scheme",
  "title_text": "Robust Diamond Quantum Sensing in Double-Quantum 4-Ramsey Interferometry by Dual-Feedback Scheme",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:01Z",
  "url": "https://research.draconitic.com/paper/3vx902v20chre",
  "venue": "arXiv",
  "versions": []
}