{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:O4NGBNFQWY2NM3DZ4KIM2XLFU3","short_pith_number":"pith:O4NGBNFQ","canonical_record":{"source":{"id":"1808.08370","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-08-25T07:45:49Z","cross_cats_sorted":[],"title_canon_sha256":"7f7ea76cbaca5f0367d2cb29a700aed06ff73c0693424511404d5bdaf1cfa371","abstract_canon_sha256":"5c0cb4181cc666fb463bd3db973299c1d6d893ff2e7a6bf6ebc9ff08738a64db"},"schema_version":"1.0"},"canonical_sha256":"771a60b4b0b634d66c79e290cd5d65a6fdfa5c415e09a7ca86fdebcce7f74da4","source":{"kind":"arxiv","id":"1808.08370","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1808.08370","created_at":"2026-05-17T23:57:08Z"},{"alias_kind":"arxiv_version","alias_value":"1808.08370v1","created_at":"2026-05-17T23:57:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1808.08370","created_at":"2026-05-17T23:57:08Z"},{"alias_kind":"pith_short_12","alias_value":"O4NGBNFQWY2N","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_16","alias_value":"O4NGBNFQWY2NM3DZ","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_8","alias_value":"O4NGBNFQ","created_at":"2026-05-18T12:32:40Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:O4NGBNFQWY2NM3DZ4KIM2XLFU3","target":"record","payload":{"canonical_record":{"source":{"id":"1808.08370","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-08-25T07:45:49Z","cross_cats_sorted":[],"title_canon_sha256":"7f7ea76cbaca5f0367d2cb29a700aed06ff73c0693424511404d5bdaf1cfa371","abstract_canon_sha256":"5c0cb4181cc666fb463bd3db973299c1d6d893ff2e7a6bf6ebc9ff08738a64db"},"schema_version":"1.0"},"canonical_sha256":"771a60b4b0b634d66c79e290cd5d65a6fdfa5c415e09a7ca86fdebcce7f74da4","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:57:08.564900Z","signature_b64":"Phl69C73yagmAba+8V+g11BDgjUwsx5VDAtd9kVyxGkneM5vJPgTknpGkTX3b2lKM3tnxKHva+eePyd0U5NSCg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"771a60b4b0b634d66c79e290cd5d65a6fdfa5c415e09a7ca86fdebcce7f74da4","last_reissued_at":"2026-05-17T23:57:08.564521Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:57:08.564521Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1808.08370","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:57:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"XK5F6fFBnO+oETysvtrgN47fEWOSMrK8kDUNFEqi8Am0gRzqoh5pFfa7ii+lzFDPYCk0wisb4+5oOV2Ltv2pBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-29T21:55:25.973876Z"},"content_sha256":"b7cb25d03a9714d20c2335a66b856270fc31e9923ce667e01f847f41af4bd3ac","schema_version":"1.0","event_id":"sha256:b7cb25d03a9714d20c2335a66b856270fc31e9923ce667e01f847f41af4bd3ac"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:O4NGBNFQWY2NM3DZ4KIM2XLFU3","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Optimal conditions for Bell test using spontaneous parametric down-conversion sources","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Hirotaka Terai, Kazuhiro Hayasaka, Kentaro Wakui, Masahide Sasaki, Masahiro Takeoka, Mikio Fujiwara, Shigehito Miki, Yoshiaki Tsujimoto","submitted_at":"2018-08-25T07:45:49Z","abstract_excerpt":"We theoretically and experimentally investigate the optimal conditions for the Bell experiment using spontaneous parametric down conversion (SPDC) sources. In theory, we show that relatively large average photon number (typically $\\sim$0.5) is desirable to observe the maximum violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality. In experiment, we perform the Bell experiment without postselection using polarization entangled photon pairs at 1550 nm telecommunication wavelength generated from SPDC sources. While the violation of the CHSH inequality is not directly observed due to the ov"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1808.08370","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":""},"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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:57:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"5aaVwy+ZYOMQTH7n2kM75LCfQ3JVKgO0flp/PDOg0zUg7YXupl99JbqBAH7J+MXUV/ZzIFnq3qfo4m2OJiIaCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-29T21:55:25.974525Z"},"content_sha256":"ccad858aed7878a95697f64d6c404f48e70f2b98a7aae288bad707af68daede6","schema_version":"1.0","event_id":"sha256:ccad858aed7878a95697f64d6c404f48e70f2b98a7aae288bad707af68daede6"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/O4NGBNFQWY2NM3DZ4KIM2XLFU3/bundle.json","state_url":"https://pith.science/pith/O4NGBNFQWY2NM3DZ4KIM2XLFU3/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/O4NGBNFQWY2NM3DZ4KIM2XLFU3/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-05-29T21:55:25Z","links":{"resolver":"https://pith.science/pith/O4NGBNFQWY2NM3DZ4KIM2XLFU3","bundle":"https://pith.science/pith/O4NGBNFQWY2NM3DZ4KIM2XLFU3/bundle.json","state":"https://pith.science/pith/O4NGBNFQWY2NM3DZ4KIM2XLFU3/state.json","well_known_bundle":"https://pith.science/.well-known/pith/O4NGBNFQWY2NM3DZ4KIM2XLFU3/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:O4NGBNFQWY2NM3DZ4KIM2XLFU3","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":"5c0cb4181cc666fb463bd3db973299c1d6d893ff2e7a6bf6ebc9ff08738a64db","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-08-25T07:45:49Z","title_canon_sha256":"7f7ea76cbaca5f0367d2cb29a700aed06ff73c0693424511404d5bdaf1cfa371"},"schema_version":"1.0","source":{"id":"1808.08370","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1808.08370","created_at":"2026-05-17T23:57:08Z"},{"alias_kind":"arxiv_version","alias_value":"1808.08370v1","created_at":"2026-05-17T23:57:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1808.08370","created_at":"2026-05-17T23:57:08Z"},{"alias_kind":"pith_short_12","alias_value":"O4NGBNFQWY2N","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_16","alias_value":"O4NGBNFQWY2NM3DZ","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_8","alias_value":"O4NGBNFQ","created_at":"2026-05-18T12:32:40Z"}],"graph_snapshots":[{"event_id":"sha256:ccad858aed7878a95697f64d6c404f48e70f2b98a7aae288bad707af68daede6","target":"graph","created_at":"2026-05-17T23:57:08Z","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 theoretically and experimentally investigate the optimal conditions for the Bell experiment using spontaneous parametric down conversion (SPDC) sources. In theory, we show that relatively large average photon number (typically $\\sim$0.5) is desirable to observe the maximum violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality. In experiment, we perform the Bell experiment without postselection using polarization entangled photon pairs at 1550 nm telecommunication wavelength generated from SPDC sources. While the violation of the CHSH inequality is not directly observed due to the ov","authors_text":"Hirotaka Terai, Kazuhiro Hayasaka, Kentaro Wakui, Masahide Sasaki, Masahiro Takeoka, Mikio Fujiwara, Shigehito Miki, Yoshiaki Tsujimoto","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-08-25T07:45:49Z","title":"Optimal conditions for Bell test using spontaneous parametric down-conversion sources"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1808.08370","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:b7cb25d03a9714d20c2335a66b856270fc31e9923ce667e01f847f41af4bd3ac","target":"record","created_at":"2026-05-17T23:57:08Z","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":"5c0cb4181cc666fb463bd3db973299c1d6d893ff2e7a6bf6ebc9ff08738a64db","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-08-25T07:45:49Z","title_canon_sha256":"7f7ea76cbaca5f0367d2cb29a700aed06ff73c0693424511404d5bdaf1cfa371"},"schema_version":"1.0","source":{"id":"1808.08370","kind":"arxiv","version":1}},"canonical_sha256":"771a60b4b0b634d66c79e290cd5d65a6fdfa5c415e09a7ca86fdebcce7f74da4","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"771a60b4b0b634d66c79e290cd5d65a6fdfa5c415e09a7ca86fdebcce7f74da4","first_computed_at":"2026-05-17T23:57:08.564521Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:57:08.564521Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Phl69C73yagmAba+8V+g11BDgjUwsx5VDAtd9kVyxGkneM5vJPgTknpGkTX3b2lKM3tnxKHva+eePyd0U5NSCg==","signature_status":"signed_v1","signed_at":"2026-05-17T23:57:08.564900Z","signed_message":"canonical_sha256_bytes"},"source_id":"1808.08370","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:b7cb25d03a9714d20c2335a66b856270fc31e9923ce667e01f847f41af4bd3ac","sha256:ccad858aed7878a95697f64d6c404f48e70f2b98a7aae288bad707af68daede6"],"state_sha256":"7516a3f4020aff8fad404a6c25cd13399d3564b45c3910cce70cba4fa42dc4d6"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1LFuVyf6GSos8mDa1LjFh1+IP7TtH+kE6u6WXsjG2An7ScjConOXAHgvf6ezt0CxmYMYENhKJ1aCfHHNyBfgDQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-29T21:55:25.978080Z","bundle_sha256":"634ee322fc305feda0f61faa63b1a78d0387e13d3ddd06528ade797fee178cdd"}}