{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2017:E7DANQ7YKCVR5LIOH53DH4CPA6","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"b202af17bfe2634cc6069557c9f3511edcb17a85927839ebd5e620d12954a217","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2017-07-03T16:52:37Z","title_canon_sha256":"7dc6da415c59865d1e5730034f635ef8ca07445fcd72ffbfeb9a3c44cf359bb8"},"schema_version":"1.0","source":{"id":"1707.00646","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1707.00646","created_at":"2026-05-18T00:30:01Z"},{"alias_kind":"arxiv_version","alias_value":"1707.00646v2","created_at":"2026-05-18T00:30:01Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1707.00646","created_at":"2026-05-18T00:30:01Z"},{"alias_kind":"pith_short_12","alias_value":"E7DANQ7YKCVR","created_at":"2026-05-18T12:31:12Z"},{"alias_kind":"pith_short_16","alias_value":"E7DANQ7YKCVR5LIO","created_at":"2026-05-18T12:31:12Z"},{"alias_kind":"pith_short_8","alias_value":"E7DANQ7Y","created_at":"2026-05-18T12:31:12Z"}],"graph_snapshots":[{"event_id":"sha256:056ecf09b399c06d846a4b36a98bd220c1522c4d1415be3e543c0cf30cd59155","target":"graph","created_at":"2026-05-18T00:30:01Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"The highly forbidden $^2$S$_{1/2} \\rightarrow ^2$F$_{7/2}$ electric octupole transition in $^{171}$Yb$^+$ is a potential candidate for a redefinition of the SI second. We present a measurement of the absolute frequency of this optical transition, performed using a frequency link to International Atomic Time to provide traceability to the SI second. The $^{171}$Yb$^+$ optical frequency standard was operated for 76% of a 25-day period, with the absolute frequency measured to be 642 121 496 772 645.14(26) Hz. The fractional uncertainty of $4.0 \\times 10 ^{-16}$ is comparable to that of the best p","authors_text":"Antoine Rolland, Charles F. A. Baynham, Fred Baynes, Helen S. Margolis, Jonathan M. Jones, Kai Bongs, Patrick E. G. Baird, Patrick Gill, Peter B. R. Nisbet-Jones, Rachel M. Godun, Steven A. King","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2017-07-03T16:52:37Z","title":"Absolute frequency measurement of the $^2$S$_{1/2} \\rightarrow ^2$F$_{7/2}$ optical clock transition in $^{171}$Yb$^+$ with an uncertainty of $4\\times 10^{-16}$ using a frequency link to International Atomic Time"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1707.00646","kind":"arxiv","version":2},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:be30b17b7d5b02509ba432a77ee1bb838809eb0722fffc5f765a31bc17e4ef0f","target":"record","created_at":"2026-05-18T00:30:01Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"b202af17bfe2634cc6069557c9f3511edcb17a85927839ebd5e620d12954a217","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2017-07-03T16:52:37Z","title_canon_sha256":"7dc6da415c59865d1e5730034f635ef8ca07445fcd72ffbfeb9a3c44cf359bb8"},"schema_version":"1.0","source":{"id":"1707.00646","kind":"arxiv","version":2}},"canonical_sha256":"27c606c3f850ab1ead0e3f7633f04f07a70cb6192fd3c2fdda68ecf0d2b53202","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"27c606c3f850ab1ead0e3f7633f04f07a70cb6192fd3c2fdda68ecf0d2b53202","first_computed_at":"2026-05-18T00:30:01.653364Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:30:01.653364Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"njFQLJYowWyYm3zMxgYn/o0EE+lmDgVXWIjUqKqnbODtOpEswwqmpBI637x/m+VopLT/YshMM9G+x7loBXUYBA==","signature_status":"signed_v1","signed_at":"2026-05-18T00:30:01.654013Z","signed_message":"canonical_sha256_bytes"},"source_id":"1707.00646","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:be30b17b7d5b02509ba432a77ee1bb838809eb0722fffc5f765a31bc17e4ef0f","sha256:056ecf09b399c06d846a4b36a98bd220c1522c4d1415be3e543c0cf30cd59155"],"state_sha256":"02b9f16284565eacd1a8d0116eb7bcdaf8ac30a9029c66a066d3ce741981c565"}