{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:IZWXPBLLC5LIV27ZFODSM2N7TT","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":"41aa18c0cee1f3833a90c4f9d47d14d966fecdc90fbd9906585c4ef4cf4d1d73","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-04-29T10:10:08Z","title_canon_sha256":"78b176446d955af6e6c9de79572f4eb9251afce2624ea4d172f744e235d58bae"},"schema_version":"1.0","source":{"id":"1304.7609","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1304.7609","created_at":"2026-05-18T03:10:26Z"},{"alias_kind":"arxiv_version","alias_value":"1304.7609v1","created_at":"2026-05-18T03:10:26Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1304.7609","created_at":"2026-05-18T03:10:26Z"},{"alias_kind":"pith_short_12","alias_value":"IZWXPBLLC5LI","created_at":"2026-05-18T12:27:49Z"},{"alias_kind":"pith_short_16","alias_value":"IZWXPBLLC5LIV27Z","created_at":"2026-05-18T12:27:49Z"},{"alias_kind":"pith_short_8","alias_value":"IZWXPBLL","created_at":"2026-05-18T12:27:49Z"}],"graph_snapshots":[{"event_id":"sha256:b6cd014769fb45eb1c9b9baa3f34881b2e70cb65a073ce9440f2cc4e886edbe7","target":"graph","created_at":"2026-05-18T03:10:26Z","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 show why and when entanglement is needed for quantum-enhanced precision measurements, and which type of entanglement is useful. We give a simple, intuitive construction that shows how entanglement transforms parallel estimation strategies into sequential ones of same precision. We employ this argument to generalize conventional quantum metrology, to identify a class of noise whose effects can be easily managed, and to treat the case of indistinguishable probes (such as interferometry with light).","authors_text":"Lorenzo Maccone","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-04-29T10:10:08Z","title":"Quantum metrology: why entanglement?"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1304.7609","kind":"arxiv","version":1},"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":"sha256:57904ae597534dee448dcb440f53a67d8be741c6ef76c2cbc74fbeac782591ac","target":"record","created_at":"2026-05-18T03:10:26Z","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":"41aa18c0cee1f3833a90c4f9d47d14d966fecdc90fbd9906585c4ef4cf4d1d73","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-04-29T10:10:08Z","title_canon_sha256":"78b176446d955af6e6c9de79572f4eb9251afce2624ea4d172f744e235d58bae"},"schema_version":"1.0","source":{"id":"1304.7609","kind":"arxiv","version":1}},"canonical_sha256":"466d77856b17568aebf92b872669bf9ce925dc5e0b30fd47b98b756b488dc13c","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"466d77856b17568aebf92b872669bf9ce925dc5e0b30fd47b98b756b488dc13c","first_computed_at":"2026-05-18T03:10:26.535560Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:10:26.535560Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"7pV+KJPlKlP8tEEYWkdWF1uYtb0/lME3wyn7ioiPuwkW0+lZVZ0X0TdV6JRj0CB6BHB6ct9mKsJq4Z5Tgy5uAw==","signature_status":"signed_v1","signed_at":"2026-05-18T03:10:26.536433Z","signed_message":"canonical_sha256_bytes"},"source_id":"1304.7609","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:57904ae597534dee448dcb440f53a67d8be741c6ef76c2cbc74fbeac782591ac","sha256:b6cd014769fb45eb1c9b9baa3f34881b2e70cb65a073ce9440f2cc4e886edbe7"],"state_sha256":"058baf8bae57ea13daec549e0cdebb5b4cecf718d417c42da4c9d7e5fa38c0f8"}