{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2013:753OJZY4EOAWF6I2HXAUIILDOU","short_pith_number":"pith:753OJZY4","canonical_record":{"source":{"id":"1311.5809","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-11-22T16:50:39Z","cross_cats_sorted":[],"title_canon_sha256":"4bd7c68f058ac8b3f4b89ab2e0ee595f85688f092aa779bf5613b0bbe22146d5","abstract_canon_sha256":"731a449eb1c42e162fa13d967337d102acf798ea5a5e3733c9e6dc3d8f7e527d"},"schema_version":"1.0"},"canonical_sha256":"ff76e4e71c238162f91a3dc1442163752fc5962da0ed948b8051ebb601adfe25","source":{"kind":"arxiv","id":"1311.5809","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1311.5809","created_at":"2026-05-18T00:19:14Z"},{"alias_kind":"arxiv_version","alias_value":"1311.5809v1","created_at":"2026-05-18T00:19:14Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1311.5809","created_at":"2026-05-18T00:19:14Z"},{"alias_kind":"pith_short_12","alias_value":"753OJZY4EOAW","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_16","alias_value":"753OJZY4EOAWF6I2","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_8","alias_value":"753OJZY4","created_at":"2026-05-18T12:27:36Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2013:753OJZY4EOAWF6I2HXAUIILDOU","target":"record","payload":{"canonical_record":{"source":{"id":"1311.5809","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-11-22T16:50:39Z","cross_cats_sorted":[],"title_canon_sha256":"4bd7c68f058ac8b3f4b89ab2e0ee595f85688f092aa779bf5613b0bbe22146d5","abstract_canon_sha256":"731a449eb1c42e162fa13d967337d102acf798ea5a5e3733c9e6dc3d8f7e527d"},"schema_version":"1.0"},"canonical_sha256":"ff76e4e71c238162f91a3dc1442163752fc5962da0ed948b8051ebb601adfe25","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:19:14.550690Z","signature_b64":"aJWDWV32frABNVKM6kWrxgviWqtgch9TGugpmbrNbH3e53uLrHjljIeiNMRkGeDHxkG9+30v5EBVRqu1ieV0Bg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"ff76e4e71c238162f91a3dc1442163752fc5962da0ed948b8051ebb601adfe25","last_reissued_at":"2026-05-18T00:19:14.549945Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:19:14.549945Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1311.5809","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":"2026-05-18T00:19:14Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"JY3o5bhaxFJf+G3rnAZuSLrsD60hJ3AulBQ/bbrjmX6Bx19i1uJY/eaCUP2+DYMWicU59k/G2R2PUYRqzGHyCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-08T12:13:28.305567Z"},"content_sha256":"359591c006d3fca5eb81daffa2fabe9783964d7ade0d1a0da6af8d614f6e1dc8","schema_version":"1.0","event_id":"sha256:359591c006d3fca5eb81daffa2fabe9783964d7ade0d1a0da6af8d614f6e1dc8"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2013:753OJZY4EOAWF6I2HXAUIILDOU","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Entangling power of two-qubit gates on mixed states","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Chuan-Feng Li, Fernando Galve, Guang-Can Guo, Huan He, Yong-Jian Han, Zhe Guan","submitted_at":"2013-11-22T16:50:39Z","abstract_excerpt":"The ability to reach a maximally entangled state from a separable one through the use of a two-qubit unitary operator is analyzed for mixed states. This extension from the known case of pure states shows that there are at least two families of gates which are able to give maximum entangling power for all values of purity. It is notable that one of this gates coincides with a maximum discording one. We give analytical proof that such gate is indeed perfect entangler at all purities and give numerical evidence for the existence of the second one. Further, we find that there are other gates, many"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1311.5809","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":"2026-05-18T00:19:14Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"azfQcqDoEKv3hGGqyvuLytGTp9JFF9P5qQV+24XYV1fRsHgp0HGfYhtvnf86OxL2CXYrkjfXfT4m6IfVk8VKCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-08T12:13:28.305910Z"},"content_sha256":"442fe9d353b21dc9e872ae05cdee91821c78354c44efff5145ba9d11828faf27","schema_version":"1.0","event_id":"sha256:442fe9d353b21dc9e872ae05cdee91821c78354c44efff5145ba9d11828faf27"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/753OJZY4EOAWF6I2HXAUIILDOU/bundle.json","state_url":"https://pith.science/pith/753OJZY4EOAWF6I2HXAUIILDOU/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/753OJZY4EOAWF6I2HXAUIILDOU/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":"2026-06-08T12:13:28Z","links":{"resolver":"https://pith.science/pith/753OJZY4EOAWF6I2HXAUIILDOU","bundle":"https://pith.science/pith/753OJZY4EOAWF6I2HXAUIILDOU/bundle.json","state":"https://pith.science/pith/753OJZY4EOAWF6I2HXAUIILDOU/state.json","well_known_bundle":"https://pith.science/.well-known/pith/753OJZY4EOAWF6I2HXAUIILDOU/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:753OJZY4EOAWF6I2HXAUIILDOU","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":"731a449eb1c42e162fa13d967337d102acf798ea5a5e3733c9e6dc3d8f7e527d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-11-22T16:50:39Z","title_canon_sha256":"4bd7c68f058ac8b3f4b89ab2e0ee595f85688f092aa779bf5613b0bbe22146d5"},"schema_version":"1.0","source":{"id":"1311.5809","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1311.5809","created_at":"2026-05-18T00:19:14Z"},{"alias_kind":"arxiv_version","alias_value":"1311.5809v1","created_at":"2026-05-18T00:19:14Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1311.5809","created_at":"2026-05-18T00:19:14Z"},{"alias_kind":"pith_short_12","alias_value":"753OJZY4EOAW","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_16","alias_value":"753OJZY4EOAWF6I2","created_at":"2026-05-18T12:27:36Z"},{"alias_kind":"pith_short_8","alias_value":"753OJZY4","created_at":"2026-05-18T12:27:36Z"}],"graph_snapshots":[{"event_id":"sha256:442fe9d353b21dc9e872ae05cdee91821c78354c44efff5145ba9d11828faf27","target":"graph","created_at":"2026-05-18T00:19:14Z","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 ability to reach a maximally entangled state from a separable one through the use of a two-qubit unitary operator is analyzed for mixed states. This extension from the known case of pure states shows that there are at least two families of gates which are able to give maximum entangling power for all values of purity. It is notable that one of this gates coincides with a maximum discording one. We give analytical proof that such gate is indeed perfect entangler at all purities and give numerical evidence for the existence of the second one. Further, we find that there are other gates, many","authors_text":"Chuan-Feng Li, Fernando Galve, Guang-Can Guo, Huan He, Yong-Jian Han, Zhe Guan","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-11-22T16:50:39Z","title":"Entangling power of two-qubit gates on mixed states"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1311.5809","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":"sha256:359591c006d3fca5eb81daffa2fabe9783964d7ade0d1a0da6af8d614f6e1dc8","target":"record","created_at":"2026-05-18T00:19:14Z","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":"731a449eb1c42e162fa13d967337d102acf798ea5a5e3733c9e6dc3d8f7e527d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2013-11-22T16:50:39Z","title_canon_sha256":"4bd7c68f058ac8b3f4b89ab2e0ee595f85688f092aa779bf5613b0bbe22146d5"},"schema_version":"1.0","source":{"id":"1311.5809","kind":"arxiv","version":1}},"canonical_sha256":"ff76e4e71c238162f91a3dc1442163752fc5962da0ed948b8051ebb601adfe25","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"ff76e4e71c238162f91a3dc1442163752fc5962da0ed948b8051ebb601adfe25","first_computed_at":"2026-05-18T00:19:14.549945Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:19:14.549945Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"aJWDWV32frABNVKM6kWrxgviWqtgch9TGugpmbrNbH3e53uLrHjljIeiNMRkGeDHxkG9+30v5EBVRqu1ieV0Bg==","signature_status":"signed_v1","signed_at":"2026-05-18T00:19:14.550690Z","signed_message":"canonical_sha256_bytes"},"source_id":"1311.5809","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:359591c006d3fca5eb81daffa2fabe9783964d7ade0d1a0da6af8d614f6e1dc8","sha256:442fe9d353b21dc9e872ae05cdee91821c78354c44efff5145ba9d11828faf27"],"state_sha256":"bd79d3b1a5d59c3604dbfac953b20476ba3c4cc67ad43e3853cdf0e94980e9b7"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"B0ETHLt8ntdBkS3loRsI8OT+1pKLPpZnfIgPRD48np4K+mEkJIzxDXqEBp9mSTPMUlUQp9R7y/X+4sE54mzSDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-08T12:13:28.307791Z","bundle_sha256":"9788ece1c6cf9f497bda8ff5f4e1c6b344007d7d0acce417a5a6b553831550dc"}}