{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2011:EPQWH5ZQ45UCUZSQBVFHAXDV4P","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":"f0c9bca7cda14eab689d5c8b7fe0337658b9ca6c106d7a29b82e7d918be486cb","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2011-02-23T10:36:55Z","title_canon_sha256":"1d741c9209d7290e2593e66553b864a87c5dda67e4feea4b2655f799e372b028"},"schema_version":"1.0","source":{"id":"1102.4710","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1102.4710","created_at":"2026-05-18T04:28:07Z"},{"alias_kind":"arxiv_version","alias_value":"1102.4710v1","created_at":"2026-05-18T04:28:07Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1102.4710","created_at":"2026-05-18T04:28:07Z"},{"alias_kind":"pith_short_12","alias_value":"EPQWH5ZQ45UC","created_at":"2026-05-18T12:26:28Z"},{"alias_kind":"pith_short_16","alias_value":"EPQWH5ZQ45UCUZSQ","created_at":"2026-05-18T12:26:28Z"},{"alias_kind":"pith_short_8","alias_value":"EPQWH5ZQ","created_at":"2026-05-18T12:26:28Z"}],"graph_snapshots":[{"event_id":"sha256:4d69f553acb21934d6829b1f8244e9899bdce7e075bf6901ea82f1c02d686ca8","target":"graph","created_at":"2026-05-18T04:28:07Z","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":"Like entanglement, quantum discord quantifies the quantum correlations. Unlike entanglement, whose detection is extremely difficult, the quantum discord of an arbitrary bipartite state allows itself to be detected perfectly by a single observable, the quantum discord witness. In particular, we report a single observable whose expectation value provides a necessary and sufficient condition for the vanishing quantum discord of an arbitrary bipartite unknown state with four copies. A quantum circuit is designed to measure the quantum discord witness by using only local qubit-measurements.","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":"2011-02-23T10:36:55Z","title":"Witnessing the quantum discord of all the unknown states"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1102.4710","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:e248ef7ba13955326ada4d84b15660487328a59b5d8ad12d00c08441107c2f5f","target":"record","created_at":"2026-05-18T04:28:07Z","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":"f0c9bca7cda14eab689d5c8b7fe0337658b9ca6c106d7a29b82e7d918be486cb","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2011-02-23T10:36:55Z","title_canon_sha256":"1d741c9209d7290e2593e66553b864a87c5dda67e4feea4b2655f799e372b028"},"schema_version":"1.0","source":{"id":"1102.4710","kind":"arxiv","version":1}},"canonical_sha256":"23e163f730e7682a66500d4a705c75e3c30590b3a89f6db8e6ea3223a6765543","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"23e163f730e7682a66500d4a705c75e3c30590b3a89f6db8e6ea3223a6765543","first_computed_at":"2026-05-18T04:28:07.544463Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T04:28:07.544463Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"rbm/Aca9xMkBJ16jSE6v6V6yvxKnX8F/6OATKxu5Y47XSWarmydJpT1lk7V4R3Oq5d/UQ/X3qJ0KZ7wpRGgxDA==","signature_status":"signed_v1","signed_at":"2026-05-18T04:28:07.545047Z","signed_message":"canonical_sha256_bytes"},"source_id":"1102.4710","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e248ef7ba13955326ada4d84b15660487328a59b5d8ad12d00c08441107c2f5f","sha256:4d69f553acb21934d6829b1f8244e9899bdce7e075bf6901ea82f1c02d686ca8"],"state_sha256":"fd54280dc07a07638fc9c8cfa5f8c04377a3fe77168c51782c325c43c2f89611"}