{
  "annotation_id": "d91ffbb8-04f3-4cb0-a977-4e60cc11c8dc",
  "date_created": "2026-02-17T05:53:20.462000Z",
  "date_modified": "2026-02-17T05:53:20.462000Z",
  "file_hash": "2c664274ef2030f586ebea5d5662a0cfb63ca4926e8e616253f458cecd712cd3",
  "private": false,
  "record": {
    "abstract": "We present a systematic study of the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in MnBi$_2$Te$_4$ films under both dark and illuminated conditions. In the dark, the intrinsic magnetism of MnBi$_2$Te$_4$ is shown to yield a stronger anisotropic RKKY spin model compared to nonmagnetic topological insulators, providing a clear signature for differentiating these systems. Furthermore, key band properties -- such as energy gap, band degeneracy/splitting, and topological deformations of the Fermi surface -- imprint distinct signatures on the RKKY interaction, enabling clear discrimination between even- and odd-septuple-layer (SL) films. This discrimination manifests in multiple ways: through the Fermi-energy dependence or spatial oscillations of the interaction for impurities on the same surface, or via the presence versus absence of spin-frustrated terms for those on different surfaces. Under off-resonant circularly polarized light, we track photoinduced topological phase transitions and identify two characteristic signatures at the phase boundary: a sign reversal in spin-frustrated terms and a dip in collinear RKKY components. These serve as fingerprints for circular-polarization-chirality-dependent topological transitions in even- and odd-SL films, respectively. Overall, this work establishes RKKY interactions as a sensitive magnetic probe for revealing both distinctive band properties and light-driven phase transitions in MnBi$_2$Te$_4$ films, thereby complementing conventional electrical measurements while providing new insights into the influence of intrinsic magnetism on the surface-state band structure.",
    "arxiv_id": "2601.09303",
    "authors": [
      "Ya-Xi Li",
      "Rui-Qiang Wang",
      "Ming-Xun Deng",
      "Hou-Jian Duan"
    ],
    "categories": [
      "cond-mat.mes-hall",
      "cond-mat.mtrl-sci"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "title": "RKKY signatures as a probe of band properties and photoinduced topological phase transitions in MnBi$_2$Te$_4$ films",
    "url": "https://arxiv.org/abs/2601.09303",
    "version": "v1"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "62006f9e-e7e1-4084-b225-a3c9493f738b",
    "id": "arXiv Dataset",
    "type": "Model",
    "variant": "snapshot-2026-01-17",
    "version": "0.1.0"
  },
  "user_id": 1000002
}