{
  "abstract": "We calculate the low-temperature superheating field $B_{\\rm sh}$ of clean superconductors near the boundary between type-I and type-II superconductivity, with particular emphasis on Nb. Ginzburg--Landau theory is not applicable at low temperatures, while previous microscopic calculations have been limited to either the large-$κ$ regime or the dirty limit. The clean, low-$κ$ regime relevant to Nb has therefore remained unresolved. We solve the self-consistent nonlinear nonlocal Eilenberger problem for the Meissner state and then analyze its stability against small perturbations. For a Nb-like material with $κ_{\\rm GL}=0.7$, we obtain $B_{\\rm sh}\\simeq 290\\,{\\rm mT}$ at $T/T_c=0.2$, using $B_{c0}\\simeq 200\\,{\\rm mT}$. For a TESLA-shaped Nb accelerator cavity, this corresponds to an intrinsic Meissner-stability limit of about $67\\,{\\rm MV/m}$.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.10420",
  "author_total": 1,
  "authors": [
    {
      "name": "Takayuki Kubo"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/51073c8ffcgvz.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.10420",
  "fulltext_url": null,
  "id": "51073c8ffcgvz",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.10420",
  "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.supr-con"
    ],
    [
      "arxiv",
      "physics.acc-ph"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2606.10420",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-22",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/51073c8ffcgvz.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:34Z",
      "native_id": "2606.10420",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.10420"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.acc-ph",
      "subfield": "applied-instrumentation"
    },
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.supr-con",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Superheating field of clean superconductors near the type-I--type-II boundary: the low-temperature Meissner stability limit of niobium",
  "title_text": "Superheating field of clean superconductors near the type-I--type-II boundary: the low-temperature Meissner stability limit of niobium",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:34Z",
  "url": "https://research.draconitic.com/paper/51073c8ffcgvz",
  "venue": "arXiv",
  "versions": []
}