{
  "abstract": "Although quantum geometry plays an established role in electronic transport and optical responses, the contribution of the time-reversal-odd Riemannian connection to fully subgap responses remains less explored. Here we identify intrinsic second-harmonic generation in PT-symmetric antiferromagnets, predominantly governed by the real sector of the interband Hermitian connection and arising entirely from virtual interband transitions. In bilayer MnBi$_2$Te$_4$, the response persists in trivial phases but is enhanced in the layer-Chern phase and reverses sign with Néel order, offering a probe of quantum geometry and phase-sensitive readout of antiferromagnetic order without mobile carriers or real excitations.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.41167",
  "author_total": 2,
  "authors": [
    {
      "name": "Shakeel Ahmad"
    },
    {
      "name": "Fei Xue"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5rv8rscq0y0xt.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.41167",
  "fulltext_url": null,
  "id": "5rv8rscq0y0xt",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.41167",
  "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.mes-hall"
    ],
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2610.41167",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5rv8rscq0y0xt.ris",
  "sources": [
    {
      "first_seen": "2026-11-02T12:21:15Z",
      "native_id": "2610.41167",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.41167"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mes-hall",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Quantum-Geometric Subgap Second-Harmonic Generation in PT-Symmetric Antiferromagnetic Insulators",
  "title_text": "Quantum-Geometric Subgap Second-Harmonic Generation in PT-Symmetric Antiferromagnetic Insulators",
  "type": "preprint",
  "updated_at": "2026-11-04T15:20:51Z",
  "url": "https://research.draconitic.com/paper/5rv8rscq0y0xt",
  "venue": "arXiv",
  "versions": []
}