{
  "abstract": "We compare the migration of a single Cr atom on monolayer graphene, between AB-stacked layers and between AA-stacked layers, with one first-principles protocol (PBE+D3(BJ), one cell family, registry anchors and spin-state search). We find three main results. First, on the surface and in the AB gallery Cr stays magnetic and moves almost freely. On the surface the C-C bridge is the minimum in 4x4 and 5x5 cells, and the highest point we sample on a hop lies 10 meV above it (5x5). In the AB gallery Cr sits on the inversion centres of the bilayer, which form a kagome net, and hops between them over 15 meV with a moment of about 4.32 $μ_B$. Second, in the AA gallery the minimum is a nonmagnetic $η^6$-$η^6$ sandwich that pulls the layers together. Leaving it requires opening the gallery and switching Cr to a moment of 4-5 $μ_B$, so we map the path with separately relaxed spin branches. The barrier estimate is 636 meV in a 3x3 cell but 260 and 185 meV in 5x5 cells with the far-field spacing pinned and free, and it is not yet converged. At 300 K, with equal prefactors and if the spin change is not rate-limiting, Cr hops between AA layers 3-4 orders of magnitude more slowly than between AB layers, using the 5x5 AA estimates and the 3x3 AB band. These AA numbers are specific to PBE+D3: an on-site U of 1.0 eV on Cr d already makes the magnetic states the AA ground state. Third, Cr binds 246-666 meV more strongly in AA than in AB registry, so the fast AB hop requires that the layers keep their Bernal registry around Cr.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.36197",
  "author_total": 2,
  "authors": [
    {
      "name": "Mingguang Chen"
    },
    {
      "name": "Senfu Zhang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0sbg2gtb1mjtb.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.36197",
  "fulltext_url": null,
  "id": "0sbg2gtb1mjtb",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.36197",
  "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.mtrl-sci"
    ],
    [
      "openalex",
      "2505|Graphene research and applications"
    ]
  ],
  "openalex": "W7224136183",
  "pdf_url": "https://arxiv.org/pdf/2610.36197",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0sbg2gtb1mjtb.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:50Z",
      "native_id": "2610.36197",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.36197"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Confinement, registry and spin in chromium migration between graphene layers",
  "title_text": "Confinement, registry and spin in chromium migration between graphene layers",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:50Z",
  "url": "https://research.draconitic.com/paper/0sbg2gtb1mjtb",
  "venue": "arXiv",
  "versions": []
}