{
  "abstract": "Optically readable molecular spins are attractive as quantum sensors due to their nanoscale modularity, synthetic tunability, and scope for sensitive readout. In particular, photoexcited spin-triplet states in organic molecules are appealing in supporting high optical-spin contrast at room temperature. Their utility is underpinned by their coherence, which warrants a detailed understanding of it. Here, from first principles, we systematically explore the Hahn-echo decoherence of the benchmark molecular system for room-temperature optically detected spin coherence---pentacene guest molecules coupled to a para-terphenyl host. Using generalized cluster-correlation expansion methods, we investigate the mechanisms of nuclear-spin-induced decoherence from zero to high magnetic field, exploring the role of guest vs host molecules, specific nuclei, zero-field splitting interactions, and hyperfine parameters. We describe how zero-field decoherence is driven by ~6 nuclei on the guest, while high-field decoherence is driven by ~600 nuclei in the host; how the longitudinal zero-field splitting parameter, $D$, can prolong $T_2$; and the magnetic-field-dependent processes which drive decoherence. These results advance our understanding of decoherence in optically readable molecular spins, providing insight for their synthetic enhancement and deployment as quantum probes.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.16851",
  "author_total": 2,
  "authors": [
    {
      "name": "Ecaterina Păunică"
    },
    {
      "name": "Sam L. Bayliss"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3ffegtat7ssee.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.16851",
  "fulltext_url": null,
  "id": "3ffegtat7ssee",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.16851",
  "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",
      "physics.chem-ph"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "2504|Magnetism in coordination complexes"
    ]
  ],
  "openalex": "W7213408055",
  "pdf_url": "https://arxiv.org/pdf/2609.16851",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-15",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3ffegtat7ssee.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:41Z",
      "native_id": "2609.16851",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.16851"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "arxiv:physics.chem-ph",
      "subfield": "physical"
    },
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Understanding the spin coherence of molecular photoexcited triplet states from first principles",
  "title_text": "Understanding the spin coherence of molecular photoexcited triplet states from first principles",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:41Z",
  "url": "https://research.draconitic.com/paper/3ffegtat7ssee",
  "venue": "arXiv",
  "versions": []
}