{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2016:BWUM3H4NBLKMVKAXYWNQUE5ZIL","short_pith_number":"pith:BWUM3H4N","canonical_record":{"source":{"id":"1604.06400","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2016-04-21T17:57:32Z","cross_cats_sorted":["cond-mat.stat-mech"],"title_canon_sha256":"fafa7e44d261d77ee796c33952df47727f87598fa50290c8a90146773ba55739","abstract_canon_sha256":"d77b9a78a266c3c1785e51e03dba5562c2cdb2decd4a4c3502357387b13447ff"},"schema_version":"1.0"},"canonical_sha256":"0da8cd9f8d0ad4caa817c59b0a13b942e34125506de48876c278c669e8479fb2","source":{"kind":"arxiv","id":"1604.06400","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1604.06400","created_at":"2026-05-18T01:01:24Z"},{"alias_kind":"arxiv_version","alias_value":"1604.06400v2","created_at":"2026-05-18T01:01:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1604.06400","created_at":"2026-05-18T01:01:24Z"},{"alias_kind":"pith_short_12","alias_value":"BWUM3H4NBLKM","created_at":"2026-05-18T12:30:09Z"},{"alias_kind":"pith_short_16","alias_value":"BWUM3H4NBLKMVKAX","created_at":"2026-05-18T12:30:09Z"},{"alias_kind":"pith_short_8","alias_value":"BWUM3H4N","created_at":"2026-05-18T12:30:09Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2016:BWUM3H4NBLKMVKAXYWNQUE5ZIL","target":"record","payload":{"canonical_record":{"source":{"id":"1604.06400","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2016-04-21T17:57:32Z","cross_cats_sorted":["cond-mat.stat-mech"],"title_canon_sha256":"fafa7e44d261d77ee796c33952df47727f87598fa50290c8a90146773ba55739","abstract_canon_sha256":"d77b9a78a266c3c1785e51e03dba5562c2cdb2decd4a4c3502357387b13447ff"},"schema_version":"1.0"},"canonical_sha256":"0da8cd9f8d0ad4caa817c59b0a13b942e34125506de48876c278c669e8479fb2","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:01:24.149726Z","signature_b64":"KXzXUhDZqsyQSJwJvSVoMj7bVsIyB6hY/C7hm6+2hNX5Bvb1HDwraCHXNc1XslHmgiIl7pFQDkvZfQeHlEBpDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"0da8cd9f8d0ad4caa817c59b0a13b942e34125506de48876c278c669e8479fb2","last_reissued_at":"2026-05-18T01:01:24.149244Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:01:24.149244Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1604.06400","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:01:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"5NwDh62/VFdWgR1kCy07gYwlvfDbbmLpyDaUQz3bcNDyEq2jP4SjqRD4uexzXaugEpS+KrPKHcw4jOiWaOVhCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-07T10:20:18.342931Z"},"content_sha256":"d3b6b965f4093834793c7a8b02cbf1f08619dfcc194ad932ace9ce690b13961c","schema_version":"1.0","event_id":"sha256:d3b6b965f4093834793c7a8b02cbf1f08619dfcc194ad932ace9ce690b13961c"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2016:BWUM3H4NBLKMVKAXYWNQUE5ZIL","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Achieving sub-shot-noise sensing at finite temperatures","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cond-mat.stat-mech"],"primary_cat":"quant-ph","authors_text":"Anna Sanpera, Luis A. Correa, Mohammad Mehboudi","submitted_at":"2016-04-21T17:57:32Z","abstract_excerpt":"We investigate sensing of magnetic fields using quantum spin chains at finite temperature and exploit quantum phase crossovers to improve metrological bounds on the estimation of the chain parameters. In particular, we analyze the $ XX $ spin chain and show that the magnetic sensitivity of this system is dictated by its adiabatic magnetic susceptibility, which scales extensively (linearly) in the number of spins $ N $. Next, we introduce an iterative feedforward protocol that actively exploits features of quantum phase crossovers to enable super-extensive scaling of the magnetic sensitivity. M"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1604.06400","kind":"arxiv","version":2},"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":"2026-05-18T01:01:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"GGLvb3zY7VMF6iBXuk6yhmc7+yGRtEF082cCwTbV6aD8uDBZRr1SYdhe2W6/lZAhEkOgLjlNqPLVQ/0eg2WWCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-07T10:20:18.343505Z"},"content_sha256":"ce84295d1b52409897fab63ceb03a2d0074842e7d1a56cc37b76e8fea98a3de6","schema_version":"1.0","event_id":"sha256:ce84295d1b52409897fab63ceb03a2d0074842e7d1a56cc37b76e8fea98a3de6"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/BWUM3H4NBLKMVKAXYWNQUE5ZIL/bundle.json","state_url":"https://pith.science/pith/BWUM3H4NBLKMVKAXYWNQUE5ZIL/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/BWUM3H4NBLKMVKAXYWNQUE5ZIL/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":"2026-06-07T10:20:18Z","links":{"resolver":"https://pith.science/pith/BWUM3H4NBLKMVKAXYWNQUE5ZIL","bundle":"https://pith.science/pith/BWUM3H4NBLKMVKAXYWNQUE5ZIL/bundle.json","state":"https://pith.science/pith/BWUM3H4NBLKMVKAXYWNQUE5ZIL/state.json","well_known_bundle":"https://pith.science/.well-known/pith/BWUM3H4NBLKMVKAXYWNQUE5ZIL/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2016:BWUM3H4NBLKMVKAXYWNQUE5ZIL","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":"d77b9a78a266c3c1785e51e03dba5562c2cdb2decd4a4c3502357387b13447ff","cross_cats_sorted":["cond-mat.stat-mech"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2016-04-21T17:57:32Z","title_canon_sha256":"fafa7e44d261d77ee796c33952df47727f87598fa50290c8a90146773ba55739"},"schema_version":"1.0","source":{"id":"1604.06400","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1604.06400","created_at":"2026-05-18T01:01:24Z"},{"alias_kind":"arxiv_version","alias_value":"1604.06400v2","created_at":"2026-05-18T01:01:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1604.06400","created_at":"2026-05-18T01:01:24Z"},{"alias_kind":"pith_short_12","alias_value":"BWUM3H4NBLKM","created_at":"2026-05-18T12:30:09Z"},{"alias_kind":"pith_short_16","alias_value":"BWUM3H4NBLKMVKAX","created_at":"2026-05-18T12:30:09Z"},{"alias_kind":"pith_short_8","alias_value":"BWUM3H4N","created_at":"2026-05-18T12:30:09Z"}],"graph_snapshots":[{"event_id":"sha256:ce84295d1b52409897fab63ceb03a2d0074842e7d1a56cc37b76e8fea98a3de6","target":"graph","created_at":"2026-05-18T01:01:24Z","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 investigate sensing of magnetic fields using quantum spin chains at finite temperature and exploit quantum phase crossovers to improve metrological bounds on the estimation of the chain parameters. In particular, we analyze the $ XX $ spin chain and show that the magnetic sensitivity of this system is dictated by its adiabatic magnetic susceptibility, which scales extensively (linearly) in the number of spins $ N $. Next, we introduce an iterative feedforward protocol that actively exploits features of quantum phase crossovers to enable super-extensive scaling of the magnetic sensitivity. M","authors_text":"Anna Sanpera, Luis A. Correa, Mohammad Mehboudi","cross_cats":["cond-mat.stat-mech"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2016-04-21T17:57:32Z","title":"Achieving sub-shot-noise sensing at finite temperatures"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1604.06400","kind":"arxiv","version":2},"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:d3b6b965f4093834793c7a8b02cbf1f08619dfcc194ad932ace9ce690b13961c","target":"record","created_at":"2026-05-18T01:01:24Z","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":"d77b9a78a266c3c1785e51e03dba5562c2cdb2decd4a4c3502357387b13447ff","cross_cats_sorted":["cond-mat.stat-mech"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2016-04-21T17:57:32Z","title_canon_sha256":"fafa7e44d261d77ee796c33952df47727f87598fa50290c8a90146773ba55739"},"schema_version":"1.0","source":{"id":"1604.06400","kind":"arxiv","version":2}},"canonical_sha256":"0da8cd9f8d0ad4caa817c59b0a13b942e34125506de48876c278c669e8479fb2","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"0da8cd9f8d0ad4caa817c59b0a13b942e34125506de48876c278c669e8479fb2","first_computed_at":"2026-05-18T01:01:24.149244Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:01:24.149244Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"KXzXUhDZqsyQSJwJvSVoMj7bVsIyB6hY/C7hm6+2hNX5Bvb1HDwraCHXNc1XslHmgiIl7pFQDkvZfQeHlEBpDQ==","signature_status":"signed_v1","signed_at":"2026-05-18T01:01:24.149726Z","signed_message":"canonical_sha256_bytes"},"source_id":"1604.06400","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d3b6b965f4093834793c7a8b02cbf1f08619dfcc194ad932ace9ce690b13961c","sha256:ce84295d1b52409897fab63ceb03a2d0074842e7d1a56cc37b76e8fea98a3de6"],"state_sha256":"41934cbb98bc760295d072d3a83bcbc28d8df53a52ba7b950864a49f2a55a05d"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"kKNdwPEwn+u3dmH3vtOmQimCiFk+qZeweK9RVLHotKMPK+fUuiTLwoDwEvx2eEggWImrrcAjBGrNPbwlBMMtCA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-07T10:20:18.346559Z","bundle_sha256":"c6e39c405dd3fdae09b62d8f6569ed0da972a7413023d856120c7131be99788b"}}