{"paper":{"title":"A thorium-229 optical nuclear clock with feedback loop","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["nucl-ex","quant-ph"],"primary_cat":"physics.atom-ph","authors_text":"A. Hellerschmied, A. Niessner, B. Gerstenecker, E. Peik, F. Schaden, F. Schneider, G. A. Kazakov, G. Zitzer, H. Denker, I. Morawetz, J. Premper, J. Schlachet-L\\'epinay, J. Tiedau, K. Beeks, L. Toscani De Col, M. Bartokos, M. Cizek, M. Matus, M. Pimon, M. V. Okhapkin, N. Sempelmann, O. Cip, S. Lahs, T. Lercher, T. Riebner, T. Schumm, V. Lal, V. Petrov","submitted_at":"2026-06-03T15:15:56Z","abstract_excerpt":"The laser-accessible nuclear transition in the thorium-229 isotope has been identified as a promising candidate for the realization of an optical nuclear clock. Such a nuclear clock might rival or outperform current optical clocks based on electron-shell transitions in atoms or ions, is expected to be more robust against external perturbations, and provides enhanced sensitivity in clock-based tests of fundamental principles of physics. Here, we implement a thorium-229 nuclear clock by stabilizing a continuous-wave laser to the 148 nm nuclear transition with rapid feedback based on continuous a"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.04997","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2606.04997/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}