{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2025:6ELZCZUE7VTFHV37BUZAHHBLKD","short_pith_number":"pith:6ELZCZUE","schema_version":"1.0","canonical_sha256":"f117916684fd6653d77f0d32039c2b50fcb0c3bfc8a4a99a8de32c467305a586","source":{"kind":"arxiv","id":"2501.11908","version":1},"attestation_state":"computed","paper":{"title":"Observation of Subnatural-Linewidth Biphotons In a Two-Level Atomic Ensemble","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["quant-ph"],"primary_cat":"physics.atom-ph","authors_text":"Chih-Sung Chuu, Chin-Te Wu, Ite A. Yu, Jyun-Kai Lin, Ravikumar Chinnarasu, Shengwang Du, Tzu-Hsiang Chien","submitted_at":"2025-01-21T06:00:05Z","abstract_excerpt":"Biphotons and single photons with narrow bandwidths and long coherence times are essential to the realization of long-distance quantum communication (LDQC) and linear optical quantum computing (LOQC). In this Letter, we manipulate the biphoton wave functions of the spontaneous four-wave mixing in a two-level atomic ensemble with a single-laser pump scheme. Our innovative experimental approach enables the generation of biphotons with a sub-MHz bandwidth of 0.36 MHz, a record spectral brightness of $2.28\\times10^7$${\\rm s}^{-1}{\\rm mW}^{-1}{\\rm MHz}^{-1}$, and a temporally symmetric wave packet "},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"2501.11908","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.atom-ph","submitted_at":"2025-01-21T06:00:05Z","cross_cats_sorted":["quant-ph"],"title_canon_sha256":"d911b2d74b4f083127a98025ae42500e318b8e398fb573e4516b1784ab6f8a5f","abstract_canon_sha256":"f6c03f180b904298ef49b31581a957932474135dd2c48d09b443bf33b079d2e6"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T10:03:15.753455Z","signature_b64":"Iz0umWLB1Snzcpars2Tp93TVsX/GHtU9T+rM1IV0GTurABJuFglv1cQow3wWrFj+5+FILhE5LZsSf+UDlWuZBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"f117916684fd6653d77f0d32039c2b50fcb0c3bfc8a4a99a8de32c467305a586","last_reissued_at":"2026-07-05T10:03:15.753038Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T10:03:15.753038Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Observation of Subnatural-Linewidth Biphotons In a Two-Level Atomic Ensemble","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["quant-ph"],"primary_cat":"physics.atom-ph","authors_text":"Chih-Sung Chuu, Chin-Te Wu, Ite A. Yu, Jyun-Kai Lin, Ravikumar Chinnarasu, Shengwang Du, Tzu-Hsiang Chien","submitted_at":"2025-01-21T06:00:05Z","abstract_excerpt":"Biphotons and single photons with narrow bandwidths and long coherence times are essential to the realization of long-distance quantum communication (LDQC) and linear optical quantum computing (LOQC). In this Letter, we manipulate the biphoton wave functions of the spontaneous four-wave mixing in a two-level atomic ensemble with a single-laser pump scheme. Our innovative experimental approach enables the generation of biphotons with a sub-MHz bandwidth of 0.36 MHz, a record spectral brightness of $2.28\\times10^7$${\\rm s}^{-1}{\\rm mW}^{-1}{\\rm MHz}^{-1}$, and a temporally symmetric wave packet "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2501.11908","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2501.11908/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"},"aliases":[{"alias_kind":"arxiv","alias_value":"2501.11908","created_at":"2026-07-05T10:03:15.753095+00:00"},{"alias_kind":"arxiv_version","alias_value":"2501.11908v1","created_at":"2026-07-05T10:03:15.753095+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2501.11908","created_at":"2026-07-05T10:03:15.753095+00:00"},{"alias_kind":"pith_short_12","alias_value":"6ELZCZUE7VTF","created_at":"2026-07-05T10:03:15.753095+00:00"},{"alias_kind":"pith_short_16","alias_value":"6ELZCZUE7VTFHV37","created_at":"2026-07-05T10:03:15.753095+00:00"},{"alias_kind":"pith_short_8","alias_value":"6ELZCZUE","created_at":"2026-07-05T10:03:15.753095+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/6ELZCZUE7VTFHV37BUZAHHBLKD","json":"https://pith.science/pith/6ELZCZUE7VTFHV37BUZAHHBLKD.json","graph_json":"https://pith.science/api/pith-number/6ELZCZUE7VTFHV37BUZAHHBLKD/graph.json","events_json":"https://pith.science/api/pith-number/6ELZCZUE7VTFHV37BUZAHHBLKD/events.json","paper":"https://pith.science/paper/6ELZCZUE"},"agent_actions":{"view_html":"https://pith.science/pith/6ELZCZUE7VTFHV37BUZAHHBLKD","download_json":"https://pith.science/pith/6ELZCZUE7VTFHV37BUZAHHBLKD.json","view_paper":"https://pith.science/paper/6ELZCZUE","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=2501.11908&json=true","fetch_graph":"https://pith.science/api/pith-number/6ELZCZUE7VTFHV37BUZAHHBLKD/graph.json","fetch_events":"https://pith.science/api/pith-number/6ELZCZUE7VTFHV37BUZAHHBLKD/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/6ELZCZUE7VTFHV37BUZAHHBLKD/action/timestamp_anchor","attest_storage":"https://pith.science/pith/6ELZCZUE7VTFHV37BUZAHHBLKD/action/storage_attestation","attest_author":"https://pith.science/pith/6ELZCZUE7VTFHV37BUZAHHBLKD/action/author_attestation","sign_citation":"https://pith.science/pith/6ELZCZUE7VTFHV37BUZAHHBLKD/action/citation_signature","submit_replication":"https://pith.science/pith/6ELZCZUE7VTFHV37BUZAHHBLKD/action/replication_record"}},"created_at":"2026-07-05T10:03:15.753095+00:00","updated_at":"2026-07-05T10:03:15.753095+00:00"}