{
  "abstract": "Intrinsic electron localization in amorphous silica (a-SiO2) contributes to charge trapping and defect generation in silica-based electronic materials - a phenomenon that degrades logic-device performance but can be exploited for memory applications. However, the structural distribution of one- and two-electron traps remains incompletely characterized, largely because the disordered covalent network of a-SiO2 spans a vast configurational space. To address this, we perform statistical sampling to select a representative 200-model subset of defect-free bulk a-SiO2 structures from a structurally converged parent set of 2512 models, generated via classical melt-quench molecular dynamics simulations. We then characterize the intrinsic one- and two-electron traps in this subset using HSE06 density functional theory calculations. Analysis of neutral precursor sites shows that trapping propensity is not determined by a universal O-Si-O angle or Si-O bond length; it is controlled by the accessibility of the relaxed trap geometry, requiring both local strain and medium-range network flexibility. Single electrons predominantly form edge-centred polarons on distorted SiO4 tetrahedra, with occupied states 3.1-4.3 eV below the conduction band minimum. Injection of a second electron drives stronger lattice relaxation, most commonly Si-O bond elongation leading to rupture, thereby forming threefold-coordinated-Si (Si3) bipolarons and, in some cases, Si-Si-bonded bipolaron configurations. The calculated bipolaron energy ranges are consistent with optical absorption features at 3.7, 4.7, and 6.4 eV associated with intrinsic electron localization.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.04652",
  "author_total": 3,
  "authors": [
    {
      "name": "Robin Delhomme"
    },
    {
      "name": "Jonathon Cottom"
    },
    {
      "name": "Emilia Olsson"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/99jsn1pvjshmt.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.04652",
  "fulltext_url": null,
  "id": "99jsn1pvjshmt",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.04652",
  "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",
      "cond-mat.mtrl-sci"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.04652",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/99jsn1pvjshmt.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T15:21:25Z",
      "native_id": "2611.04652",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.04652"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Statistically Robust Characterization of Polaron and Bipolaron Intrinsic Traps in Amorphous Silica Reveals the Role of Network Flexibility in Electron Localisation",
  "title_text": "Statistically Robust Characterization of Polaron and Bipolaron Intrinsic Traps in Amorphous Silica Reveals the Role of Network Flexibility in Electron Localisation",
  "type": "preprint",
  "updated_at": "2026-11-06T18:21:01Z",
  "url": "https://research.draconitic.com/paper/99jsn1pvjshmt",
  "venue": "arXiv",
  "versions": []
}