{
  "abstract": "We report a demonstration of a self-shunted superconducting flux qubit (SSFQ) as an ultracompact, strongly anharmonic, and long-lifetime qubit by using the full epitaxially grown NbN/AlN/NbN Josephson junctions. The NbN-junction-based SSFQ achieved a high anharmonicity of 797 MHz as well as drastically reduced footprint of the qubit compared to capacitively shunted (C-shunt) flux qubits with a large shunt capacitor. The lifetime of the SSFQ reached 13 - 25 $μ$s, which is comparable to or relatively higher than that of NbN-based C-shunt flux qubits and Al-based flux qubits with more than 10 times smaller junctions. This indicates that the large epitaxial NbN-based junction can be adopted for SSFQ as well as merged-element transmon with the relatively large junctions. The results presented in this work will offer a new choice of the scalable qubits as well as the material platform toward the realization of large-scale superconducting quantum computers.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.04821",
  "author_total": 8,
  "authors": [
    {
      "name": "Tokunoshin Uchida"
    },
    {
      "name": "Shingo Nozaki"
    },
    {
      "name": "Daiki Kurihara"
    },
    {
      "name": "Hiroki Kutsuma"
    },
    {
      "name": "Shotaro Shirai"
    },
    {
      "name": "Atsushi Noguchi"
    },
    {
      "name": "Hirotaka Terai"
    },
    {
      "name": "Taro Yamashita"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7k8f2j0f11dv0.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.04821",
  "fulltext_url": null,
  "id": "7k8f2j0f11dv0",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.04821",
  "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.supr-con"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Information and Cryptography"
    ]
  ],
  "openalex": "W7220738489",
  "pdf_url": "https://arxiv.org/pdf/2610.04821",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7k8f2j0f11dv0.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:01Z",
      "native_id": "2610.04821",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.04821"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.supr-con",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Epitaxial NbN-junction-based self-shunted superconducting flux qubit with high anharmonicity",
  "title_text": "Epitaxial NbN-junction-based self-shunted superconducting flux qubit with high anharmonicity",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:01Z",
  "url": "https://research.draconitic.com/paper/7k8f2j0f11dv0",
  "venue": "arXiv",
  "versions": []
}