{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2011:EJSW527C6IFQ3BDIRJVKULOV5Z","short_pith_number":"pith:EJSW527C","canonical_record":{"source":{"id":"1107.5458","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2011-07-27T12:42:56Z","cross_cats_sorted":[],"title_canon_sha256":"898936427abee0cf4f9c73e369a2b36b9fe983f3d5eba8647d32f4f2e40fd028","abstract_canon_sha256":"848593c1b61de81bdb74683fbe27bc05d8484ea5a9406012398bf7e45f412d72"},"schema_version":"1.0"},"canonical_sha256":"22656eebe2f20b0d84688a6aaa2dd5ee5f4f28e5f9044dc43f6cc373d843ad0d","source":{"kind":"arxiv","id":"1107.5458","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1107.5458","created_at":"2026-05-18T02:01:08Z"},{"alias_kind":"arxiv_version","alias_value":"1107.5458v3","created_at":"2026-05-18T02:01:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1107.5458","created_at":"2026-05-18T02:01:08Z"},{"alias_kind":"pith_short_12","alias_value":"EJSW527C6IFQ","created_at":"2026-05-18T12:26:28Z"},{"alias_kind":"pith_short_16","alias_value":"EJSW527C6IFQ3BDI","created_at":"2026-05-18T12:26:28Z"},{"alias_kind":"pith_short_8","alias_value":"EJSW527C","created_at":"2026-05-18T12:26:28Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2011:EJSW527C6IFQ3BDIRJVKULOV5Z","target":"record","payload":{"canonical_record":{"source":{"id":"1107.5458","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2011-07-27T12:42:56Z","cross_cats_sorted":[],"title_canon_sha256":"898936427abee0cf4f9c73e369a2b36b9fe983f3d5eba8647d32f4f2e40fd028","abstract_canon_sha256":"848593c1b61de81bdb74683fbe27bc05d8484ea5a9406012398bf7e45f412d72"},"schema_version":"1.0"},"canonical_sha256":"22656eebe2f20b0d84688a6aaa2dd5ee5f4f28e5f9044dc43f6cc373d843ad0d","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:01:08.988717Z","signature_b64":"0pwKeCMJ++ZHbMuA94SKWgMMLk5Wr3/NV5axHZNW/29w4Uvfg2+nraMiD29wb4/WN0SRbKWYnBJn0V8IcjqnBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"22656eebe2f20b0d84688a6aaa2dd5ee5f4f28e5f9044dc43f6cc373d843ad0d","last_reissued_at":"2026-05-18T02:01:08.988160Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:01:08.988160Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1107.5458","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T02:01:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Jo5FXrmlXVFsJrRV4OgyIPQ14VefuPjYv3jwRQtV9swugs00hzdswJVAbNI/+g9QjUY3KmldXGeBsWCDIGFuBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T22:26:32.344229Z"},"content_sha256":"4412f62c4b7b8c6acc127a9a65c64b8e5db83d85575fbd480796a4a6da3907c0","schema_version":"1.0","event_id":"sha256:4412f62c4b7b8c6acc127a9a65c64b8e5db83d85575fbd480796a4a6da3907c0"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2011:EJSW527C6IFQ3BDIRJVKULOV5Z","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Observable estimation of entanglement of formation and quantum discord for bipartite mixed quantum states","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Chengjie Zhang, C.H. Oh, Qing Chen, Sixia Yu","submitted_at":"2011-07-27T12:42:56Z","abstract_excerpt":"We present observable lower and upper bounds for the entanglement of formation (EOF) and quantum discord (QD), which facilitates estimates of EOF and QD for arbitrary experimental unknown states in finite-dimensional bipartite systems. These bounds can be easily obtained by a few experimental measurements on a twofold copy $\\varrho\\otimes\\varrho$ of the mixed states. Based on our results, we use the experimental measurement data of the real experiment given by Schmid \\textit{et al.} [Phys. Rev. Lett. \\textbf{101}, 260505 (2008)] to obtain the lower and upper bounds of EOF and QD for the experi"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1107.5458","kind":"arxiv","version":3},"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":"2026-05-18T02:01:08Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Uaj0ZTgNLCMRHiI6elAceYfv1T0F7llu4e73I7u6Zu2vdDSb4oBGtXfoicTULrDJAo8tRo58VIeIpOr0fqJrCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T22:26:32.344876Z"},"content_sha256":"e0b598fd5ef6b4f5baab7239f4b965bb788d03a1c4271cbd980bd2323d1de476","schema_version":"1.0","event_id":"sha256:e0b598fd5ef6b4f5baab7239f4b965bb788d03a1c4271cbd980bd2323d1de476"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/EJSW527C6IFQ3BDIRJVKULOV5Z/bundle.json","state_url":"https://pith.science/pith/EJSW527C6IFQ3BDIRJVKULOV5Z/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/EJSW527C6IFQ3BDIRJVKULOV5Z/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":"2026-05-31T22:26:32Z","links":{"resolver":"https://pith.science/pith/EJSW527C6IFQ3BDIRJVKULOV5Z","bundle":"https://pith.science/pith/EJSW527C6IFQ3BDIRJVKULOV5Z/bundle.json","state":"https://pith.science/pith/EJSW527C6IFQ3BDIRJVKULOV5Z/state.json","well_known_bundle":"https://pith.science/.well-known/pith/EJSW527C6IFQ3BDIRJVKULOV5Z/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2011:EJSW527C6IFQ3BDIRJVKULOV5Z","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":"848593c1b61de81bdb74683fbe27bc05d8484ea5a9406012398bf7e45f412d72","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2011-07-27T12:42:56Z","title_canon_sha256":"898936427abee0cf4f9c73e369a2b36b9fe983f3d5eba8647d32f4f2e40fd028"},"schema_version":"1.0","source":{"id":"1107.5458","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1107.5458","created_at":"2026-05-18T02:01:08Z"},{"alias_kind":"arxiv_version","alias_value":"1107.5458v3","created_at":"2026-05-18T02:01:08Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1107.5458","created_at":"2026-05-18T02:01:08Z"},{"alias_kind":"pith_short_12","alias_value":"EJSW527C6IFQ","created_at":"2026-05-18T12:26:28Z"},{"alias_kind":"pith_short_16","alias_value":"EJSW527C6IFQ3BDI","created_at":"2026-05-18T12:26:28Z"},{"alias_kind":"pith_short_8","alias_value":"EJSW527C","created_at":"2026-05-18T12:26:28Z"}],"graph_snapshots":[{"event_id":"sha256:e0b598fd5ef6b4f5baab7239f4b965bb788d03a1c4271cbd980bd2323d1de476","target":"graph","created_at":"2026-05-18T02:01:08Z","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 present observable lower and upper bounds for the entanglement of formation (EOF) and quantum discord (QD), which facilitates estimates of EOF and QD for arbitrary experimental unknown states in finite-dimensional bipartite systems. These bounds can be easily obtained by a few experimental measurements on a twofold copy $\\varrho\\otimes\\varrho$ of the mixed states. Based on our results, we use the experimental measurement data of the real experiment given by Schmid \\textit{et al.} [Phys. Rev. Lett. \\textbf{101}, 260505 (2008)] to obtain the lower and upper bounds of EOF and QD for the experi","authors_text":"Chengjie Zhang, C.H. Oh, Qing Chen, Sixia Yu","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2011-07-27T12:42:56Z","title":"Observable estimation of entanglement of formation and quantum discord for bipartite mixed quantum states"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1107.5458","kind":"arxiv","version":3},"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":"sha256:4412f62c4b7b8c6acc127a9a65c64b8e5db83d85575fbd480796a4a6da3907c0","target":"record","created_at":"2026-05-18T02:01:08Z","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":"848593c1b61de81bdb74683fbe27bc05d8484ea5a9406012398bf7e45f412d72","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2011-07-27T12:42:56Z","title_canon_sha256":"898936427abee0cf4f9c73e369a2b36b9fe983f3d5eba8647d32f4f2e40fd028"},"schema_version":"1.0","source":{"id":"1107.5458","kind":"arxiv","version":3}},"canonical_sha256":"22656eebe2f20b0d84688a6aaa2dd5ee5f4f28e5f9044dc43f6cc373d843ad0d","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"22656eebe2f20b0d84688a6aaa2dd5ee5f4f28e5f9044dc43f6cc373d843ad0d","first_computed_at":"2026-05-18T02:01:08.988160Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:01:08.988160Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"0pwKeCMJ++ZHbMuA94SKWgMMLk5Wr3/NV5axHZNW/29w4Uvfg2+nraMiD29wb4/WN0SRbKWYnBJn0V8IcjqnBw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:01:08.988717Z","signed_message":"canonical_sha256_bytes"},"source_id":"1107.5458","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:4412f62c4b7b8c6acc127a9a65c64b8e5db83d85575fbd480796a4a6da3907c0","sha256:e0b598fd5ef6b4f5baab7239f4b965bb788d03a1c4271cbd980bd2323d1de476"],"state_sha256":"ed5a02c45835ef7c3ad3ae517dabbfdcdfb475de2d8dac88e82b9e9cfdcde800"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ItVGISuPe+rZ5/tRsNIAaF0USZ9ECAxn5VDjNETXmdf2URs4k6DV4oWsF3a2IY6eP1R9iByiDKOaGCqOEB4WCg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-31T22:26:32.348237Z","bundle_sha256":"b7b3f2a8274aceecce03f4ceebabba53318cb64a5adcabb44af67c6a66e01a99"}}