{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2014:LAJ7MT6SZYXXKPYQT72NJ4H6ZE","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":"bfc1b4c00799ad0800b20b456fd46e9151465e788fe0096d548bd8ab38798de5","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2014-05-10T06:09:03Z","title_canon_sha256":"ab3f84b665f4a46e9f3c5dc13cf5119350ffa9486cb3695a6bd58209257ba05f"},"schema_version":"1.0","source":{"id":"1405.2397","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1405.2397","created_at":"2026-05-18T02:51:41Z"},{"alias_kind":"arxiv_version","alias_value":"1405.2397v1","created_at":"2026-05-18T02:51:41Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1405.2397","created_at":"2026-05-18T02:51:41Z"},{"alias_kind":"pith_short_12","alias_value":"LAJ7MT6SZYXX","created_at":"2026-05-18T12:28:35Z"},{"alias_kind":"pith_short_16","alias_value":"LAJ7MT6SZYXXKPYQ","created_at":"2026-05-18T12:28:35Z"},{"alias_kind":"pith_short_8","alias_value":"LAJ7MT6S","created_at":"2026-05-18T12:28:35Z"}],"graph_snapshots":[{"event_id":"sha256:c3d4ab341f2a59ed854c5cad63f9cd274d3620c398aaf73ada5dbc2b1ae06200","target":"graph","created_at":"2026-05-18T02:51:41Z","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 derive a general expression of the quantum Fisher information for a Mach-Zehnder interferometer, with the port inputs of an \\emph{arbitrary} pure state and a squeezed thermal state. We find that the standard quantum limit can be beaten, when even or odd states are applied to the pure-state port. In particular, when the squeezed thermal state becomes a thermal state, all the even or odd states have the same quantum Fisher information for given photon numbers. For a squeezed thermal state, optimal even or odd states are needed to approach the Heisenberg limit. As examples, we consider several","authors_text":"Franco Nori, Jie-Qiao Liao, Qing-Shou Tan, Xiaoguang Wang","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2014-05-10T06:09:03Z","title":"Enhanced interferometry using squeezed thermal states and even or odd states"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1405.2397","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:c28a8e3923a60d8b3d938d89e6a5126ba86ea5a6cd56131094cd2d25149bbad5","target":"record","created_at":"2026-05-18T02:51:41Z","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":"bfc1b4c00799ad0800b20b456fd46e9151465e788fe0096d548bd8ab38798de5","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2014-05-10T06:09:03Z","title_canon_sha256":"ab3f84b665f4a46e9f3c5dc13cf5119350ffa9486cb3695a6bd58209257ba05f"},"schema_version":"1.0","source":{"id":"1405.2397","kind":"arxiv","version":1}},"canonical_sha256":"5813f64fd2ce2f753f109ff4d4f0fec933b7e5c0a0802747c9924571fc4cea8d","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"5813f64fd2ce2f753f109ff4d4f0fec933b7e5c0a0802747c9924571fc4cea8d","first_computed_at":"2026-05-18T02:51:41.284524Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:51:41.284524Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"eHAl9Mamn8Mh1khaD5NzF4Yo6McMfZbjOE7IglOFwFRhhlQnwb6YOVOPQSRvzTC3PqSiwnCVmt+C5jQvJhxuBg==","signature_status":"signed_v1","signed_at":"2026-05-18T02:51:41.285091Z","signed_message":"canonical_sha256_bytes"},"source_id":"1405.2397","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:c28a8e3923a60d8b3d938d89e6a5126ba86ea5a6cd56131094cd2d25149bbad5","sha256:c3d4ab341f2a59ed854c5cad63f9cd274d3620c398aaf73ada5dbc2b1ae06200"],"state_sha256":"d89cbc2b00a65a6585c16b99167793a74118c11c6b0e349a1896299ac68d175d"}