{
  "abstract": "Telecom-band spin defects in silicon offer a compelling platform for integrated quantum networks by combining scalable silicon photonics with spin-based quantum memories and multiqubit registers. The T center and recently demonstrated Al1 center are particularly promising, but their limited coherent zero-phonon emission requires strong cavity enhancement for efficient spin-photon interfaces. Here, we inverse-design silicon nanobeam cavities for both centers using a unified adjoint-optimization framework targeting Purcell enhancement, resonance alignment, and photon extraction. For each emitter, symmetric cavities maximize Purcell enhancement, while asymmetric cavities provide directional coupling to an integrated waveguide. Three-dimensional finite-difference time-domain simulations yield loaded quality factors up to 3.25 x 10^6, Purcell factors up to 1.43 x 10^5, and cooperativities of approximately 280-5000, corresponding to cavity-coupled emission fractions exceeding 99.6%. The asymmetric cavities direct approximately 90% of emitted power into a single on-chip waveguide while maintaining cooperativity above 280. Under nanometer-scale fabrication perturbations, all four designs remain within the high-cooperativity regime, and high cooperativity persists when the cavity quality factor is constrained to a realistic absorption-limited value of 10^5. This unified, fabrication-compatible framework establishes a scalable cavity-design route for silicon telecom spin-photon interfaces and, to our knowledge, the first cavity designs for the Al1 center.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.32205",
  "author_total": 3,
  "authors": [
    {
      "name": "Nail Letty"
    },
    {
      "name": "Md Sakibul Islam"
    },
    {
      "name": "Wayesh Qarony"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/a98fhsrfdab3b.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.32205",
  "fulltext_url": null,
  "id": "a98fhsrfdab3b",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.32205",
  "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",
      "quant-ph"
    ],
    [
      "openalex",
      "2208|Photonic and Optical Devices"
    ]
  ],
  "openalex": "W7214746708",
  "pdf_url": "https://arxiv.org/pdf/2609.32205",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/a98fhsrfdab3b.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:12Z",
      "native_id": "2609.32205",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.32205"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Inverse-Designed Nanobeam Cavities for High-Cooperativity Spin-Photon Interfaces in Silicon",
  "title_text": "Inverse-Designed Nanobeam Cavities for High-Cooperativity Spin-Photon Interfaces in Silicon",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:12Z",
  "url": "https://research.draconitic.com/paper/a98fhsrfdab3b",
  "venue": "arXiv",
  "versions": []
}