{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:MUBRDJFQYLSJSWPUK7QWKHWLWM","short_pith_number":"pith:MUBRDJFQ","canonical_record":{"source":{"id":"1808.07073","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-08-21T18:04:42Z","cross_cats_sorted":[],"title_canon_sha256":"1ad0808bfdc450b37a6c364604c0d24299443c2177c6f5ee43c434d81a3b5dd2","abstract_canon_sha256":"14a5b9f6fef53de2dafeadcb7266b9a213c4e3ada5322945688c09d8805c023d"},"schema_version":"1.0"},"canonical_sha256":"650311a4b0c2e49959f457e1651ecbb31b97ce0fec12e565f95fa14b72e3bdcf","source":{"kind":"arxiv","id":"1808.07073","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1808.07073","created_at":"2026-05-18T00:07:32Z"},{"alias_kind":"arxiv_version","alias_value":"1808.07073v1","created_at":"2026-05-18T00:07:32Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1808.07073","created_at":"2026-05-18T00:07:32Z"},{"alias_kind":"pith_short_12","alias_value":"MUBRDJFQYLSJ","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_16","alias_value":"MUBRDJFQYLSJSWPU","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_8","alias_value":"MUBRDJFQ","created_at":"2026-05-18T12:32:40Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:MUBRDJFQYLSJSWPUK7QWKHWLWM","target":"record","payload":{"canonical_record":{"source":{"id":"1808.07073","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-08-21T18:04:42Z","cross_cats_sorted":[],"title_canon_sha256":"1ad0808bfdc450b37a6c364604c0d24299443c2177c6f5ee43c434d81a3b5dd2","abstract_canon_sha256":"14a5b9f6fef53de2dafeadcb7266b9a213c4e3ada5322945688c09d8805c023d"},"schema_version":"1.0"},"canonical_sha256":"650311a4b0c2e49959f457e1651ecbb31b97ce0fec12e565f95fa14b72e3bdcf","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:07:32.001129Z","signature_b64":"EuFK6EBW5xKudSh2yquWtekIlY3wAwx+Tpy26fxOQkIAuVtLbYE7MTAhFcXA2vnoqPT0wwPHr0j6JGgVrX+cCA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"650311a4b0c2e49959f457e1651ecbb31b97ce0fec12e565f95fa14b72e3bdcf","last_reissued_at":"2026-05-18T00:07:32.000500Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:07:32.000500Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1808.07073","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":"2026-05-18T00:07:32Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"otduEZQi+thkc2utCMWJOxApezsfzCjqvoSn7umfV7/tbuMivBztFWZg3u52laOdz/S5X4XB9Gs/muy2mTBrCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T22:59:29.511656Z"},"content_sha256":"bc7fd69e8422e70ce2e07e5e1b99ef1e835fac32cb5e967d6fe5b82231af79e1","schema_version":"1.0","event_id":"sha256:bc7fd69e8422e70ce2e07e5e1b99ef1e835fac32cb5e967d6fe5b82231af79e1"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:MUBRDJFQYLSJSWPUK7QWKHWLWM","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Experimental construction of a versatile four-photon source","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Anton\\'in \\v{C}ernoch, Karel Lemr, Karol Bartkiewicz","submitted_at":"2018-08-21T18:04:42Z","abstract_excerpt":"The paper discusses technical aspects of constructing a highly versatile multi-photon source. The source is able to generate up to four photons which is sufficient for a large number of quantum communications protocols. It can be set to generate separable, partially-entangled or maximally-entangled photon pairs with tunable amount of purity. Furthermore, the two generated pairs can be prepared in different quantum states. In this paper, we provide all the necessary information needed for construction and alignment of the source. To prove the working principle, we also provide results of thorou"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1808.07073","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":"2026-05-18T00:07:32Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Lr6h7P8fVBMUnpnt9aOwnYSu7VVk0s+rPWM5WNBDyevUT9sBwtXPRfIKZnK2Ed9l8q9R2Nf8nc2/kkESvH/eDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T22:59:29.512359Z"},"content_sha256":"54a64b2e2db754589f811ef7d553ef1914c7e76056891b313ba98d74a4f8a466","schema_version":"1.0","event_id":"sha256:54a64b2e2db754589f811ef7d553ef1914c7e76056891b313ba98d74a4f8a466"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/MUBRDJFQYLSJSWPUK7QWKHWLWM/bundle.json","state_url":"https://pith.science/pith/MUBRDJFQYLSJSWPUK7QWKHWLWM/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/MUBRDJFQYLSJSWPUK7QWKHWLWM/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":"2026-05-26T22:59:29Z","links":{"resolver":"https://pith.science/pith/MUBRDJFQYLSJSWPUK7QWKHWLWM","bundle":"https://pith.science/pith/MUBRDJFQYLSJSWPUK7QWKHWLWM/bundle.json","state":"https://pith.science/pith/MUBRDJFQYLSJSWPUK7QWKHWLWM/state.json","well_known_bundle":"https://pith.science/.well-known/pith/MUBRDJFQYLSJSWPUK7QWKHWLWM/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:MUBRDJFQYLSJSWPUK7QWKHWLWM","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":"14a5b9f6fef53de2dafeadcb7266b9a213c4e3ada5322945688c09d8805c023d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-08-21T18:04:42Z","title_canon_sha256":"1ad0808bfdc450b37a6c364604c0d24299443c2177c6f5ee43c434d81a3b5dd2"},"schema_version":"1.0","source":{"id":"1808.07073","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1808.07073","created_at":"2026-05-18T00:07:32Z"},{"alias_kind":"arxiv_version","alias_value":"1808.07073v1","created_at":"2026-05-18T00:07:32Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1808.07073","created_at":"2026-05-18T00:07:32Z"},{"alias_kind":"pith_short_12","alias_value":"MUBRDJFQYLSJ","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_16","alias_value":"MUBRDJFQYLSJSWPU","created_at":"2026-05-18T12:32:40Z"},{"alias_kind":"pith_short_8","alias_value":"MUBRDJFQ","created_at":"2026-05-18T12:32:40Z"}],"graph_snapshots":[{"event_id":"sha256:54a64b2e2db754589f811ef7d553ef1914c7e76056891b313ba98d74a4f8a466","target":"graph","created_at":"2026-05-18T00:07:32Z","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":"The paper discusses technical aspects of constructing a highly versatile multi-photon source. The source is able to generate up to four photons which is sufficient for a large number of quantum communications protocols. It can be set to generate separable, partially-entangled or maximally-entangled photon pairs with tunable amount of purity. Furthermore, the two generated pairs can be prepared in different quantum states. In this paper, we provide all the necessary information needed for construction and alignment of the source. To prove the working principle, we also provide results of thorou","authors_text":"Anton\\'in \\v{C}ernoch, Karel Lemr, Karol Bartkiewicz","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-08-21T18:04:42Z","title":"Experimental construction of a versatile four-photon source"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1808.07073","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:bc7fd69e8422e70ce2e07e5e1b99ef1e835fac32cb5e967d6fe5b82231af79e1","target":"record","created_at":"2026-05-18T00:07:32Z","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":"14a5b9f6fef53de2dafeadcb7266b9a213c4e3ada5322945688c09d8805c023d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2018-08-21T18:04:42Z","title_canon_sha256":"1ad0808bfdc450b37a6c364604c0d24299443c2177c6f5ee43c434d81a3b5dd2"},"schema_version":"1.0","source":{"id":"1808.07073","kind":"arxiv","version":1}},"canonical_sha256":"650311a4b0c2e49959f457e1651ecbb31b97ce0fec12e565f95fa14b72e3bdcf","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"650311a4b0c2e49959f457e1651ecbb31b97ce0fec12e565f95fa14b72e3bdcf","first_computed_at":"2026-05-18T00:07:32.000500Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:07:32.000500Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"EuFK6EBW5xKudSh2yquWtekIlY3wAwx+Tpy26fxOQkIAuVtLbYE7MTAhFcXA2vnoqPT0wwPHr0j6JGgVrX+cCA==","signature_status":"signed_v1","signed_at":"2026-05-18T00:07:32.001129Z","signed_message":"canonical_sha256_bytes"},"source_id":"1808.07073","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:bc7fd69e8422e70ce2e07e5e1b99ef1e835fac32cb5e967d6fe5b82231af79e1","sha256:54a64b2e2db754589f811ef7d553ef1914c7e76056891b313ba98d74a4f8a466"],"state_sha256":"99c6cb18d5e5b34f5402cf6abf58b4ae4169df1d80c6884eb039fb7307dc5ea6"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"OlynuL2KUh0MJ4BzbpzcTRoj2+I8juQ7Kwj6Ue+wRn2JeMK12luFUHhd9t68pD2g1zY+PcjaDK4YTW6U4yG+DA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-26T22:59:29.516033Z","bundle_sha256":"a959abae6e9e48d33a5faeb8706dba95cdb9d4c047dc14136899bdc5c72e3cd3"}}