{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2010:MRGFHFHM3NAP4VAGGUHR44ESVX","short_pith_number":"pith:MRGFHFHM","canonical_record":{"source":{"id":"1011.6530","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2010-11-30T12:49:17Z","cross_cats_sorted":["quant-ph"],"title_canon_sha256":"f13c38ba901c37bfc93f9f52b24a4cb31c795a2c048e93f95e011df183f84048","abstract_canon_sha256":"e6bb1a7ac5f75ba0c2cf4a7a9a1bdcb4997310cd56e9415f04b3da6314066150"},"schema_version":"1.0"},"canonical_sha256":"644c5394ecdb40fe5406350f1e7092ade4a8e4c8ce70556f2b145a70d6a56ccb","source":{"kind":"arxiv","id":"1011.6530","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1011.6530","created_at":"2026-05-18T04:21:21Z"},{"alias_kind":"arxiv_version","alias_value":"1011.6530v1","created_at":"2026-05-18T04:21:21Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1011.6530","created_at":"2026-05-18T04:21:21Z"},{"alias_kind":"pith_short_12","alias_value":"MRGFHFHM3NAP","created_at":"2026-05-18T12:26:10Z"},{"alias_kind":"pith_short_16","alias_value":"MRGFHFHM3NAP4VAG","created_at":"2026-05-18T12:26:10Z"},{"alias_kind":"pith_short_8","alias_value":"MRGFHFHM","created_at":"2026-05-18T12:26:10Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2010:MRGFHFHM3NAP4VAGGUHR44ESVX","target":"record","payload":{"canonical_record":{"source":{"id":"1011.6530","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2010-11-30T12:49:17Z","cross_cats_sorted":["quant-ph"],"title_canon_sha256":"f13c38ba901c37bfc93f9f52b24a4cb31c795a2c048e93f95e011df183f84048","abstract_canon_sha256":"e6bb1a7ac5f75ba0c2cf4a7a9a1bdcb4997310cd56e9415f04b3da6314066150"},"schema_version":"1.0"},"canonical_sha256":"644c5394ecdb40fe5406350f1e7092ade4a8e4c8ce70556f2b145a70d6a56ccb","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T04:21:21.380385Z","signature_b64":"etagn7Pg/YD/8/2v1W/nTHW+eC3qkkVStP2Lu5TA7I+rNXhGdUhEjDA3sQWBPYlOR+xIbe05+p1MiSqO4aBDAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"644c5394ecdb40fe5406350f1e7092ade4a8e4c8ce70556f2b145a70d6a56ccb","last_reissued_at":"2026-05-18T04:21:21.379973Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T04:21:21.379973Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1011.6530","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":"2026-05-18T04:21:21Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"qYWpyUXqR+J369SoD4idTeVOQCSx0j7JjIm9fIF36YbW8Eq6vJOocKJRkvxDtzegEG2WZg8oOG0nhrSYaDGwDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T04:29:15.073485Z"},"content_sha256":"5e29c57fa54af940a8da01ff63b6505ad27e02effcc27b6fccca3a9613655a57","schema_version":"1.0","event_id":"sha256:5e29c57fa54af940a8da01ff63b6505ad27e02effcc27b6fccca3a9613655a57"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2010:MRGFHFHM3NAP4VAGGUHR44ESVX","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Entanglement of quantum spin systems: a valence-bond approach","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["quant-ph"],"primary_cat":"cond-mat.str-el","authors_text":"F. Alet, M. Mambrini, S. Capponi","submitted_at":"2010-11-30T12:49:17Z","abstract_excerpt":"In order to quantify entanglement between two parts of a quantum system, one of the most used estimator is the Von Neumann entropy. Unfortunately, computing this quantity for large interacting quantum spin systems remains an open issue. Faced with this difficulty, other estimators have been proposed to measure entanglement efficiently, mostly by using simulations in the valence-bond basis. We review the different proposals and try to clarify the connections between their geometric definitions and proper observables. We illustrate this analysis with new results of entanglement properties of spi"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1011.6530","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":"2026-05-18T04:21:21Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"GXSRg2tRf16OYQNmd8RfelSZEveCC8Vbw3/+SPhRORY30BG+axuvwsGZicunOq68+U5aOasZo2w4RgnKFZLfDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T04:29:15.073830Z"},"content_sha256":"b4a70fa7d58a2819cb36f80ad4f7fdba28c564a4a252bcf17456831a713568b2","schema_version":"1.0","event_id":"sha256:b4a70fa7d58a2819cb36f80ad4f7fdba28c564a4a252bcf17456831a713568b2"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/MRGFHFHM3NAP4VAGGUHR44ESVX/bundle.json","state_url":"https://pith.science/pith/MRGFHFHM3NAP4VAGGUHR44ESVX/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/MRGFHFHM3NAP4VAGGUHR44ESVX/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":"2026-06-01T04:29:15Z","links":{"resolver":"https://pith.science/pith/MRGFHFHM3NAP4VAGGUHR44ESVX","bundle":"https://pith.science/pith/MRGFHFHM3NAP4VAGGUHR44ESVX/bundle.json","state":"https://pith.science/pith/MRGFHFHM3NAP4VAGGUHR44ESVX/state.json","well_known_bundle":"https://pith.science/.well-known/pith/MRGFHFHM3NAP4VAGGUHR44ESVX/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2010:MRGFHFHM3NAP4VAGGUHR44ESVX","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":"e6bb1a7ac5f75ba0c2cf4a7a9a1bdcb4997310cd56e9415f04b3da6314066150","cross_cats_sorted":["quant-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2010-11-30T12:49:17Z","title_canon_sha256":"f13c38ba901c37bfc93f9f52b24a4cb31c795a2c048e93f95e011df183f84048"},"schema_version":"1.0","source":{"id":"1011.6530","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1011.6530","created_at":"2026-05-18T04:21:21Z"},{"alias_kind":"arxiv_version","alias_value":"1011.6530v1","created_at":"2026-05-18T04:21:21Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1011.6530","created_at":"2026-05-18T04:21:21Z"},{"alias_kind":"pith_short_12","alias_value":"MRGFHFHM3NAP","created_at":"2026-05-18T12:26:10Z"},{"alias_kind":"pith_short_16","alias_value":"MRGFHFHM3NAP4VAG","created_at":"2026-05-18T12:26:10Z"},{"alias_kind":"pith_short_8","alias_value":"MRGFHFHM","created_at":"2026-05-18T12:26:10Z"}],"graph_snapshots":[{"event_id":"sha256:b4a70fa7d58a2819cb36f80ad4f7fdba28c564a4a252bcf17456831a713568b2","target":"graph","created_at":"2026-05-18T04:21:21Z","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":"In order to quantify entanglement between two parts of a quantum system, one of the most used estimator is the Von Neumann entropy. Unfortunately, computing this quantity for large interacting quantum spin systems remains an open issue. Faced with this difficulty, other estimators have been proposed to measure entanglement efficiently, mostly by using simulations in the valence-bond basis. We review the different proposals and try to clarify the connections between their geometric definitions and proper observables. We illustrate this analysis with new results of entanglement properties of spi","authors_text":"F. Alet, M. Mambrini, S. Capponi","cross_cats":["quant-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2010-11-30T12:49:17Z","title":"Entanglement of quantum spin systems: a valence-bond approach"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1011.6530","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":"sha256:5e29c57fa54af940a8da01ff63b6505ad27e02effcc27b6fccca3a9613655a57","target":"record","created_at":"2026-05-18T04:21:21Z","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":"e6bb1a7ac5f75ba0c2cf4a7a9a1bdcb4997310cd56e9415f04b3da6314066150","cross_cats_sorted":["quant-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2010-11-30T12:49:17Z","title_canon_sha256":"f13c38ba901c37bfc93f9f52b24a4cb31c795a2c048e93f95e011df183f84048"},"schema_version":"1.0","source":{"id":"1011.6530","kind":"arxiv","version":1}},"canonical_sha256":"644c5394ecdb40fe5406350f1e7092ade4a8e4c8ce70556f2b145a70d6a56ccb","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"644c5394ecdb40fe5406350f1e7092ade4a8e4c8ce70556f2b145a70d6a56ccb","first_computed_at":"2026-05-18T04:21:21.379973Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T04:21:21.379973Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"etagn7Pg/YD/8/2v1W/nTHW+eC3qkkVStP2Lu5TA7I+rNXhGdUhEjDA3sQWBPYlOR+xIbe05+p1MiSqO4aBDAw==","signature_status":"signed_v1","signed_at":"2026-05-18T04:21:21.380385Z","signed_message":"canonical_sha256_bytes"},"source_id":"1011.6530","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:5e29c57fa54af940a8da01ff63b6505ad27e02effcc27b6fccca3a9613655a57","sha256:b4a70fa7d58a2819cb36f80ad4f7fdba28c564a4a252bcf17456831a713568b2"],"state_sha256":"cc50ac1195099e6ef9abe9730bf437b7f5a12e132902426bd92b3b0c45966b78"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"uFnxRiq36OSGsH8wuIIyHevp7cEVdwdZ87LeRl8dQZ4SlTCExSOxfSyLanB2/oJk58XkcftlE8rbA2K/RwG1DA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-01T04:29:15.075710Z","bundle_sha256":"a28e5fb40f4ca544fe782faf3daf388ae4d80183b781f343460d48874e73013a"}}