{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:QCJITJ7HPN2772LGMAF4NBGWC6","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":"6ff8ef6c679640e6e486ae64d4ab48118134305edbe9cd84ee74d80744657a8e","cross_cats_sorted":["quant-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2015-08-20T21:19:17Z","title_canon_sha256":"2b83dda7c8cd9f304b25fcb9851d31ecd10e2c590143420b892d044bc5d912e7"},"schema_version":"1.0","source":{"id":"1508.05129","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1508.05129","created_at":"2026-05-18T01:17:18Z"},{"alias_kind":"arxiv_version","alias_value":"1508.05129v2","created_at":"2026-05-18T01:17:18Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1508.05129","created_at":"2026-05-18T01:17:18Z"},{"alias_kind":"pith_short_12","alias_value":"QCJITJ7HPN27","created_at":"2026-05-18T12:29:37Z"},{"alias_kind":"pith_short_16","alias_value":"QCJITJ7HPN2772LG","created_at":"2026-05-18T12:29:37Z"},{"alias_kind":"pith_short_8","alias_value":"QCJITJ7H","created_at":"2026-05-18T12:29:37Z"}],"graph_snapshots":[{"event_id":"sha256:48729ea6478ef8ecdd2aafa6a299d62d1cf533f0ba95c10b161e59d64320cb59","target":"graph","created_at":"2026-05-18T01:17:18Z","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":"We develop differential measurement protocols that circumvent the laser noise limit in the stability of optical clock comparisons by synchronous probing of two clocks using phase-locked local oscillators. This allows for probe times longer than the laser coherence time, avoids the Dick effect, and supports Heisenberg-limited measurement precision. We present protocols for such frequency comparisons and develop numerical simulations of the protocols with realistic noise sources. These methods provide a route to reduce frequency ratio measurement durations by more than an order of magnitude.","authors_text":"David B. Hume, David R. Leibrandt","cross_cats":["quant-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2015-08-20T21:19:17Z","title":"Probing beyond the laser coherence time in optical clock comparisons"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1508.05129","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":"sha256:8488559b5faea912081f2498dce13483815f3e1301b14b63df853a053e69480d","target":"record","created_at":"2026-05-18T01:17:18Z","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":"6ff8ef6c679640e6e486ae64d4ab48118134305edbe9cd84ee74d80744657a8e","cross_cats_sorted":["quant-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2015-08-20T21:19:17Z","title_canon_sha256":"2b83dda7c8cd9f304b25fcb9851d31ecd10e2c590143420b892d044bc5d912e7"},"schema_version":"1.0","source":{"id":"1508.05129","kind":"arxiv","version":2}},"canonical_sha256":"809289a7e77b75ffe966600bc684d617a3c9c8cb1a976260cd56c34d215069f2","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"809289a7e77b75ffe966600bc684d617a3c9c8cb1a976260cd56c34d215069f2","first_computed_at":"2026-05-18T01:17:18.895884Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:17:18.895884Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"7lMlGfXfZWfFc6ehp3nuVi4FrclB7bG00ZclmrOTKBJ+Qt8PoZCF6+8uyP27f7kCz5TGEIQiQS4MbpMYAn/XAw==","signature_status":"signed_v1","signed_at":"2026-05-18T01:17:18.896441Z","signed_message":"canonical_sha256_bytes"},"source_id":"1508.05129","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:8488559b5faea912081f2498dce13483815f3e1301b14b63df853a053e69480d","sha256:48729ea6478ef8ecdd2aafa6a299d62d1cf533f0ba95c10b161e59d64320cb59"],"state_sha256":"1bb96c492e0b12634b0bf34ce9f483b657bd056b36e34f9a2fc0c0c121febf56"}