{
  "abstract": "Rare-earth-ion based molecular crystals are emerging as a promising platform for quantum information applications, combining long optical coherence times with the chemical tunability of coordination chemistry. Here we present a comprehensive optical characterisation of twelve Eu$^{3+}$-based molecular complexes, with a focus on the coherent $^{5}\\text{D}_{0} \\longrightarrow \\ ^{7}\\text{F}_{0}$ transition at $\\sim$580 nm. Judd-Ofelt analyses are performed across all complexes, providing insights into ligand-field environments, local point-group symmetries, and the resulting branching ratios of the coherent transition. We find that lower point-group symmetry (C$_1$, C$_2$) yields higher branching ratios of the $^{5}\\text{D}_{0} \\longrightarrow \\ ^{7}\\text{F}_{0}$ transition, exceeding 1\\% in several complexes. Optical inhomogeneous linewidths measured at 4.2 K reveal narrow linewidths for some complexes of below ten GHz, indicative of a highly ordered crystalline environment. Optical coherence measurements of one of the complexes, 5-Eu, yields an optical coherence time of $T_{\\text{2}}^{\\text{opt}} = 2.3~μ\\mathrm{s}$ at 4.2 K, comparable to the best-performing molecular systems reported to date. Systematic characterisation and quantitative comparison will be key to find structure-property relations guiding rational design of optimised complexes for quantum information applications.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.13664",
  "author_total": 12,
  "authors": [
    {
      "name": "Nicholas Lester Jobbitt"
    },
    {
      "name": "Sascha Weis"
    },
    {
      "name": "Timo Schweizer"
    },
    {
      "name": "Vishnu Unni Chorakkunnath"
    },
    {
      "name": "Evgenij Vasilenko"
    },
    {
      "name": "Tobias Haas"
    },
    {
      "name": "Barbora Brachnakova"
    },
    {
      "name": "Senthil Kumar Kuppusamy"
    },
    {
      "name": "Hartmut Schubert"
    },
    {
      "name": "Mario Ruben"
    },
    {
      "name": "Michael Seitz"
    },
    {
      "name": "David Hunger"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9j2t637thmjyk.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.13664",
  "fulltext_url": null,
  "id": "9j2t637thmjyk",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.13664",
  "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.optics"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "2505|Lanthanide and Transition Metal Complexes"
    ]
  ],
  "openalex": "W7221566191",
  "pdf_url": "https://arxiv.org/pdf/2610.13664",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9j2t637thmjyk.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:28:36Z",
      "native_id": "2610.13664",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.13664"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.optics",
      "subfield": "optics-photonics"
    },
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Judd-Ofelt analysis and coherent spectroscopy of europium-based molecular complexes for quantum information applications",
  "title_text": "Judd-Ofelt analysis and coherent spectroscopy of europium-based molecular complexes for quantum information applications",
  "type": "preprint",
  "updated_at": "2026-10-30T12:28:36Z",
  "url": "https://research.draconitic.com/paper/9j2t637thmjyk",
  "venue": "arXiv",
  "versions": []
}