{
  "abstract": "Flux noise is unanimously recognised as a leading dephasing mechanism for flux-tunable superconducting qubits. However, our microscopic understanding remains incomplete, and basic effects like Faraday's law of induction have only very recently come into focus. Based on a quantum geometric description of the Faraday effect, we provide an in-depth derivation of the coupling of generic magnetic sources to thin film superconducting structures, under appropriate consideration of the device geometry. We apply the resulting framework to time-varying magnetic dipoles, describing surface or substrate spins, as well as current-carrying flux lines. We show that flux noise not only affects dephasing, but also provides a fundamental limit for the qubit quality factor - notably, even when the qubit contains no loops and is thus nominally not flux-tunable. Assuming surface spins as the origin for universal flux noise, we expect that this quality factor limit might be reached in the near term. For flux lines, we formulate a minimal safety distance to conserve the qubit performance, potentially constraining the scale-up of quantum hardware. This distance is boosted in the presence of large capacitor wings typical for transmons, due to a lensing of the electromotive field which is largely independent of Meissner screening.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.03059",
  "author_total": 2,
  "authors": [
    {
      "name": "Daniel Kruti"
    },
    {
      "name": "Roman-Pascal Riwar"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/etpds7fgfrqbd.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.03059",
  "fulltext_url": null,
  "id": "etpds7fgfrqbd",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.03059",
  "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.mes-hall"
    ],
    [
      "arxiv",
      "cond-mat.supr-con"
    ],
    [
      "openalex",
      "1702|Quantum Information and Cryptography"
    ]
  ],
  "openalex": "W7208730047",
  "pdf_url": "https://arxiv.org/pdf/2609.03059",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-02",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/etpds7fgfrqbd.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:31Z",
      "native_id": "2609.03059",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.03059"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mes-hall",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Flux noise without flux tunability in superconducting qubits",
  "title_text": "Flux noise without flux tunability in superconducting qubits",
  "type": "preprint",
  "updated_at": "2026-10-30T12:18:31Z",
  "url": "https://research.draconitic.com/paper/etpds7fgfrqbd",
  "venue": "arXiv",
  "versions": []
}