{
  "abstract": "Using in situ photoemission spectroscopy and x-ray absorption spectroscopy, we investigated the thickness dependence of the electronic structure and V-V dimerization in VO$_2$/TiO$_2$ (110) ultrathin films, in which the one-dimensional V-V chains along the $c_{\\mathit{R}}$ axis lie in the film plane. In VO$_2$ $(110)_{\\mathit{R}}$ films, the reduction in dimensionality along the surface-normal direction is not expected to impose a geometric constraint on V-V dimerization, unlike in VO$_2$ $(001)_{\\mathit{R}}$ films. Nevertheless, the characteristic spectral changes associated with the temperature-driven metal-insulator transition observed in thick films persist down to 1.5 nm, whereas at 1 nm an insulating electronic phase is observed without V-V dimerization. This behavior is highly similar to that reported for VO$_2$ $(001)_{\\mathit{R}}$, suggesting that the enhancement of Mott instability resulting from reduced dimensionality is a common and essential driving force for the emergence of the nondimerized insulating phase in VO$_2$ ultrathin films. Meanwhile, unlike in VO$_2$ $(001)_{\\mathit{R}}$, the nondimerized insulating phase in VO$_2$ $(110)_{\\mathit{R}}$ coexists with the phase exhibiting the temperature-driven metal-insulator transition. Its fraction increases exponentially with decreasing thickness and becomes dominant at 1 nm. The corresponding effective critical thickness is estimated to be 2.2 nm. These results imply that the geometric orientation of the V-V chains dictates the spatial evolution of electronic phase separation via strain-mediated phase competition.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.29116",
  "author_total": 6,
  "authors": [
    {
      "name": "S. Inoue"
    },
    {
      "name": "D. Shiga"
    },
    {
      "name": "R. Hayasaka"
    },
    {
      "name": "K. Ozawa"
    },
    {
      "name": "A. F. Santander-Syro"
    },
    {
      "name": "H. Kumigashira"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/471sqz3rbj750.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.29116",
  "fulltext_url": null,
  "id": "471sqz3rbj750",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.29116",
  "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"
    ],
    [
      "arxiv",
      "cond-mat.str-el"
    ],
    [
      "openalex",
      "2507|Transition Metal Oxide Nanomaterials"
    ]
  ],
  "openalex": "W7204917957",
  "pdf_url": "https://arxiv.org/pdf/2608.29116",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-29",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/471sqz3rbj750.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:41Z",
      "native_id": "2608.29116",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.29116"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Electronic phase separation and emergence of a nondimerized insulating phase in VO$_2$ $(110)_{\\mathit{R}}$ ultrathin films",
  "title_text": "Electronic phase separation and emergence of a nondimerized insulating phase in VO_2 (110)_R ultrathin films",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:41Z",
  "url": "https://research.draconitic.com/paper/471sqz3rbj750",
  "venue": "arXiv",
  "versions": []
}