{
  "abstract": "Daylight entanglement-based free-space quantum key distribution (QKD) is limited by accidental coincidences from receiver-admitted background light. We develop and experimentally validate a receiver-level framework anchored to measured singles rates and reference coincidence components, linking receiver bandwidth, accepted temporal width, and background-noise density to Bob singles, sifted-key rate, error rate, and quantum bit error rate (QBER) in telecom-wavelength BBM92 QKD. Indoor sweeps show that the sifted-key rate saturates near the source-matched bandwidth, whereas broader bandwidth or higher background mainly increases accidental contamination. Increasing the accepted temporal width leaves Bob singles nearly unchanged but directly raises QBER by enlarging the random-overlap probability. A two-dimensional design map calculated from the model shows that the temporal-window margin contracts rapidly with increasing background-to-signal ratio, while the bandwidth margin remains comparatively broad near source-matched filtering. A rooftop experiment demonstrates daylight operation over a 10 m free-space link, yielding a mean sifted-key rate of 2,811 cps and a mean QBER of 4.43%. This framework provides a quantitative basis for choosing receiver bandwidth and temporal acceptance to meet a target QBER under specified background conditions.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.17365",
  "author_total": 5,
  "authors": [
    {
      "name": "Jiyoung Moon"
    },
    {
      "name": "Yonggi Jo"
    },
    {
      "name": "Zaeill Kim"
    },
    {
      "name": "Yong Sup Ihn"
    },
    {
      "name": "Nam Hun Park"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/c7m93na0png4s.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.17365",
  "fulltext_url": null,
  "id": "c7m93na0png4s",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.17365",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2606.17365",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/c7m93na0png4s.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:26Z",
      "native_id": "2606.17365",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.17365"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Time-spectral control of accidental coincidences in daylight entanglement-based free-space QKD",
  "title_text": "Time-spectral control of accidental coincidences in daylight entanglement-based free-space QKD",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:26Z",
  "url": "https://research.draconitic.com/paper/c7m93na0png4s",
  "venue": "arXiv",
  "versions": []
}