{"paper":{"title":"Direct comparison of a Ca+ single ion clock against a Sr optical lattice clock","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.optics","quant-ph"],"primary_cat":"physics.atom-ph","authors_text":"Asahiko Nogami, Clayton Locke, Hidekazu Hachisu, Kazuhiro Hayasaka, Kensuke Matsubara, Masatoshi Kajita, Mizuhiko Hosokawa, Shigeo Nagano, Tetsuya Ido, Ying Li","submitted_at":"2012-08-23T01:16:17Z","abstract_excerpt":"Optical frequency comparison of the 40Ca+ clock transition \\nu_{Ca} (2S1/2-2D5/2, 729nm) against the 87Sr optical lattice clock transition \\nu_{Sr}(1S0-3P0, 698nm) has resulted in a frequency ratio \\nu_{Ca} / \\nu_{Sr} = 0.957 631 202 358 049 9(2 3). The rapid nature of optical comparison allowed the statistical uncertainty of frequency ratio \\nu_{Ca} / \\nu_{Sr} to reach 1x10-15 in only 1000s and yielded a value consistent with that calculated from separate absolute frequency measurements of \\nu_{Ca} using the International Atomic Time (TAI) link. The total uncertainty of the frequency ratio us"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1208.4654","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":""},"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"}