{
  "id": "2407.11506",
  "version": "v1",
  "published": "2024-07-16T08:42:46.000Z",
  "updated": "2024-07-16T08:42:46.000Z",
  "title": "Conformational tuning of magnetic interactions in coupled nanographenes",
  "authors": [
    "Gonçalo Catarina",
    "Elia Turco",
    "Nils Krane",
    "Max Bommert",
    "Andres Ortega-Guerrero",
    "Oliver Gröning",
    "Pascal Ruffieux",
    "Roman Fasel",
    "Carlo A. Pignedoli"
  ],
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "Phenalenyl (C$_{13}$H$_9$) is an open-shell spin-$1/2$ nanographene. Using scanning tunneling microscopy (STM) inelastic electron tunneling spectroscopy (IETS), covalently-bonded phenalenyl dimers have been shown to feature conductance steps associated with singlet-triplet excitations of a spin-$1/2$ dimer with antiferromagnetic exchange. Here, we address the possibility of tuning the magnitude of the exchange interactions by varying the dihedral angle between the two molecules within a dimer. Theoretical methods, ranging from density functional theory calculations to many-body model Hamiltonians solved within different levels of approximation, are used to explain STM-IETS measurements of twisted phenalenyl dimers on a h-BN/Rh(111) surface. By means of first-principles calculations, we also propose strategies to induce sizable twist angles in surface-adsorbed phenalenyl dimers via functional groups, including a photoswitchable scheme. This work paves the way toward tuning magnetic couplings in carbon-based spin chains and two-dimensional lattices.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-07-16T08:42:46.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "magnetic interactions",
      "coupled nanographenes",
      "phenalenyl dimers",
      "conformational tuning",
      "density functional theory calculations"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}