{
  "abstract": "Many functionally important materials, such as silicon, possess high-symmetry crystal structures that forbid even-order nonlinear optical responses, thereby limiting their application in e.g., photonics and optoelectronics. Strain gradients can effectively break symmetries, activating otherwise forbidden optical responses. Although such flexo-photoresponses have attracted considerable interest recently, a comprehensive microscopic theoretical framework is still lacking. Here, we develop a first-principles approach that can systematically evaluate a wide range of flexo-photoresponses in realistic materials. By mapping strain gradients to long-wavelength phonons within the established theory of electron-phonon coupling, our approach captures the nonlocal quantum-mechanical effects of lattice deformations on nonlinear optical responses. Applying the framework to prototypical centrosymmetric materials, including Si, cubic $\\rm SrTiO_3$, and monolayer black phosphorus, we demonstrate that a strain gradients of $10^5\\sim10^6~\\rm m^{-1}$ can induce flexo-second-harmonic generation and flexo-bulk photovoltaic effects comparable to the intrinsic responses of non-centrosymmetric crystals. Our work establishes a rigorous foundation for strain gradient engineering of light-matter interactions, opening new avenues for nanoscale optomechanics, optoelectronics, and beyond.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.32341",
  "author_total": 3,
  "authors": [
    {
      "name": "Zhichao Guo"
    },
    {
      "name": "Hua Wang"
    },
    {
      "name": "Haowei Xu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8g8jqgpsm3nt0.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.32341",
  "fulltext_url": null,
  "id": "8g8jqgpsm3nt0",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.32341",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ],
    [
      "openalex",
      "2504|Multiferroics and related materials"
    ]
  ],
  "openalex": "W7223710091",
  "pdf_url": "https://arxiv.org/pdf/2610.32341",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8g8jqgpsm3nt0.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:15Z",
      "native_id": "2610.32341",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.32341"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Flexo-Photoresponses from First Principles",
  "title_text": "Flexo-Photoresponses from First Principles",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:15Z",
  "url": "https://research.draconitic.com/paper/8g8jqgpsm3nt0",
  "venue": "arXiv",
  "versions": []
}