{
  "abstract": "Two-dimensional semiconductors that simultaneously possess a direct band gap and strong spin-orbit coupling (SOC) are highly attractive for quantum optoelectronics. Using first-principles GW plus Bethe-Salpeter equation (GW-BSE) calculations, we show that monolayer WSi2P4-an experimentally accessible member of the MSi2X4 family-hosts a direct K-valley gap together with strong SOC. Its three competing polymorphs (alpha, beta and gamma) are all direct-gap semiconductors and are kinetically locked behind 1.3 eV migration barriers. The sigma_h mirror plane of the D3h of alpha and gamma phases enforces a persistent spin texture across the Brillouin zone, weakly modulated near gamma by interband SOC mixing, whereas the polar beta phase (C3v) exhibits Rashba spin splitting. SOC splits the doubly-degenerate lowest bright exciton into dark states and splits the original absorption peak into two peaks (A and B), whose relative brightness is governed by the K-valley conduction-band splitting. alpha-WSi2P4 displays the brightest Peak A because a tiny band crossing of opposite-spin branches can open a spin-allowed radiative channel. These results establish the MSi2P4 family as a phase-tunable platform for the cooperative engineering of spin texture, band splitting, and excitonic brightness within a single material system.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.38756",
  "author_total": 9,
  "authors": [
    {
      "name": "Xianbo Chenwei"
    },
    {
      "name": "Yu Zhou"
    },
    {
      "name": "Ke Wu"
    },
    {
      "name": "Gaofeng Xu"
    },
    {
      "name": "Ruixue Li"
    },
    {
      "name": "Yuan Li"
    },
    {
      "name": "Yabei Wu"
    },
    {
      "name": "Shaowen Xu"
    },
    {
      "name": "Fanhao Jia"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5xrw489acct13.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.38756",
  "fulltext_url": null,
  "id": "5xrw489acct13",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.38756",
  "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",
      "2505|2D Materials and Applications"
    ]
  ],
  "openalex": "W7215051734",
  "pdf_url": "https://arxiv.org/pdf/2609.38756",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5xrw489acct13.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:49Z",
      "native_id": "2609.38756",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.38756"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Polymorph-Tunable Spin Texture and Excitonic Structures in Monolayer WSi2P4",
  "title_text": "Polymorph-Tunable Spin Texture and Excitonic Structures in Monolayer WSi2P4",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:49Z",
  "url": "https://research.draconitic.com/paper/5xrw489acct13",
  "venue": "arXiv",
  "versions": []
}