{
  "abstract": "Altermagnetic multiferroics provide a platform where non-relativistic spin-momentum locking (SML) coexists with relativistic spin textures, yet disentangling their different origins remains challenging. Here, using first-principles density-functional-theory calculations and symmetry analysis of the multipolar expansion of the spin polarization, we investigate the altermagnetic multiferroic BaCuF4. Its dominant non-relativistic altermagnetic d-wave SML originates primarily from a CuF6 octahedral rotation coupled to the polar distortion and can therefore be reversed by ferroelectric switching. We show that spin-orbit coupling generates additional spin multipoles and, depending on the Neel-vector orientation, induces spin canting and weak ferromagnetism. By exploiting the group-subgroup relations between spin groups and magnetic space groups, we then distinguish non-relativistic altermagnetic, canting-associated, and purely relativistic contributions to the SML. We further show that this hierarchy is encoded in the nonlinear spin-photogalvanic response, whose spin projection selectively probes contributions of different origins. These results establish a direct connection between the microscopic spin texture and nonlinear spin transport in altermagnetic multiferroics.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.37763",
  "author_total": 9,
  "authors": [
    {
      "name": "Giuseppe Cuono"
    },
    {
      "name": "Subhadeep Bandyopadhyay"
    },
    {
      "name": "Amar Fakhredine"
    },
    {
      "name": "Mathews Benny"
    },
    {
      "name": "Xujia Gong"
    },
    {
      "name": "Paolo Barone"
    },
    {
      "name": "Andrea Droghetti"
    },
    {
      "name": "Carmine Autieri"
    },
    {
      "name": "Silvia Picozzi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7r3x2sehjzx65.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.37763",
  "fulltext_url": null,
  "id": "7r3x2sehjzx65",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.37763",
  "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": "W7214977350",
  "pdf_url": "https://arxiv.org/pdf/2609.37763",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-29",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7r3x2sehjzx65.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:31Z",
      "native_id": "2609.37763",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.37763"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Nonrelativistic and Relativistic Contributions to Spin-Momentum Locking and Spin Photogalvanic Effect in an Altermagnetic Multiferroic",
  "title_text": "Nonrelativistic and Relativistic Contributions to Spin-Momentum Locking and Spin Photogalvanic Effect in an Altermagnetic Multiferroic",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:31Z",
  "url": "https://research.draconitic.com/paper/7r3x2sehjzx65",
  "venue": "arXiv",
  "versions": []
}