{
  "abstract": "We report a systematic uncertainty evaluation of the $^{171}$Yb optical lattice clock NMIJ-Yb1 (NMIJ: National Metrology Institute of Japan) with a fractional frequency uncertainty of $2.6\\times10^{-17}$, improved by a factor of 3.8 compared with our previous uncertainty. The uncertainty of the lattice light shift is reduced to $1.6\\times10^{-17}$ by preparing axially sideband-cooled atoms in a shallow optical lattice. Different models to calculate the lattice light shift are compared, taking account of possible model-dependent biases due to the treatment of the radial motion of atoms trapped in the optical lattice. The uncertainty of the blackbody radiation shift reaches $7.0\\times10^{-18}$ by measuring the radiative temperature at the position of atoms with an in-vacuum temperature sensor. We also demonstrate the nearly continuous operation of NMIJ-Yb1 with an uptime of 91.3 $\\%$ for 10 days, showing the potential for future improvement of the calibration uncertainty of International Atomic Time.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.18468",
  "author_total": 7,
  "authors": [
    {
      "name": "Takumi Kobayashi"
    },
    {
      "name": "Akiko Nishiyama"
    },
    {
      "name": "Ikuhiko Saito"
    },
    {
      "name": "Daisuke Akamatsu"
    },
    {
      "name": "Akio Kawasaki"
    },
    {
      "name": "Shintaro Nagase"
    },
    {
      "name": "Masami Yasuda"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9157vca97a8c7.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.18468",
  "fulltext_url": null,
  "id": "9157vca97a8c7",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.18468",
  "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",
      "physics.atom-ph"
    ],
    [
      "openalex",
      "3107|Advanced Frequency and Time Standards"
    ]
  ],
  "openalex": "W7213528591",
  "pdf_url": "https://arxiv.org/pdf/2609.18468",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-16",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9157vca97a8c7.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:01Z",
      "native_id": "2609.18468",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.18468"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.atom-ph",
      "subfield": "amo"
    }
  ],
  "title": "Improved systematic uncertainty evaluation of the $^{171}$Yb optical lattice clock NMIJ-Yb1 with uncertainty of $2.6\\times10^{-17}$",
  "title_text": "Improved systematic uncertainty evaluation of the ^171Yb optical lattice clock NMIJ-Yb1 with uncertainty of 2.6×10^−17",
  "type": "preprint",
  "updated_at": "2026-10-30T12:22:01Z",
  "url": "https://research.draconitic.com/paper/9157vca97a8c7",
  "venue": "arXiv",
  "versions": []
}