{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:R2I5VJOWJJXJID2ZAMX6IH7G7E","short_pith_number":"pith:R2I5VJOW","canonical_record":{"source":{"id":"1807.09683","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2018-07-25T16:01:09Z","cross_cats_sorted":["cond-mat.mtrl-sci","cond-mat.supr-con"],"title_canon_sha256":"69e366e5d5270e0fbf65e8ff19e022992e678df7a0e9d15d342a95481089ecc4","abstract_canon_sha256":"9d0a683b690305d04eee944d8423dc9ee0c3308a324f9c2cf31b4c5bc56b4bb3"},"schema_version":"1.0"},"canonical_sha256":"8e91daa5d64a6e940f59032fe41fe6f911e069d0c7caed9c045888d378977ed4","source":{"kind":"arxiv","id":"1807.09683","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1807.09683","created_at":"2026-05-18T00:02:31Z"},{"alias_kind":"arxiv_version","alias_value":"1807.09683v1","created_at":"2026-05-18T00:02:31Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1807.09683","created_at":"2026-05-18T00:02:31Z"},{"alias_kind":"pith_short_12","alias_value":"R2I5VJOWJJXJ","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_16","alias_value":"R2I5VJOWJJXJID2Z","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_8","alias_value":"R2I5VJOW","created_at":"2026-05-18T12:32:50Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:R2I5VJOWJJXJID2ZAMX6IH7G7E","target":"record","payload":{"canonical_record":{"source":{"id":"1807.09683","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2018-07-25T16:01:09Z","cross_cats_sorted":["cond-mat.mtrl-sci","cond-mat.supr-con"],"title_canon_sha256":"69e366e5d5270e0fbf65e8ff19e022992e678df7a0e9d15d342a95481089ecc4","abstract_canon_sha256":"9d0a683b690305d04eee944d8423dc9ee0c3308a324f9c2cf31b4c5bc56b4bb3"},"schema_version":"1.0"},"canonical_sha256":"8e91daa5d64a6e940f59032fe41fe6f911e069d0c7caed9c045888d378977ed4","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:02:31.577937Z","signature_b64":"JjgT20JOB5jcqaibUZCzVkCV8bcGp4XrJF84anU7rJ94xAEP+wVpfjxllZccS/pO8SMdMamn9akJ87Oz1Vu4DA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"8e91daa5d64a6e940f59032fe41fe6f911e069d0c7caed9c045888d378977ed4","last_reissued_at":"2026-05-18T00:02:31.577245Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:02:31.577245Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1807.09683","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":"2026-05-18T00:02:31Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"qgGrfWqezFhmuE1Wt6lSafdufIzxgwAIx0fjRR0v2F8wgTB2hRP+Ir1efbvJcexzaNxQCnYpmJcuUXTgdPQPAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-06T13:21:44.955778Z"},"content_sha256":"23accc30e840ba8de42e1419647175cbea95ed3f472b6c498a7224a2f9013354","schema_version":"1.0","event_id":"sha256:23accc30e840ba8de42e1419647175cbea95ed3f472b6c498a7224a2f9013354"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:R2I5VJOWJJXJID2ZAMX6IH7G7E","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Temperature dependence of NMR Knight shift in pnictides: proximity to a van Hove singularity","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cond-mat.mtrl-sci","cond-mat.supr-con"],"primary_cat":"cond-mat.str-el","authors_text":"R. Nourafkan, S. Acheche","submitted_at":"2018-07-25T16:01:09Z","abstract_excerpt":"The unconventional temperature variation of the Knight shift (static spin susceptibility) that has been observed in Fe-based superconductors AFe$_2$As$_2$ (A = K, Rb, Cs) is explained in terms of proximity to a van Hove singularity. Using the Hubbard model we show that when the Fermi energy is in the vicinity of a van Hove singularity, a downturn in spin susceptibility occurs as the temperature is lowered. This behavior is characterized by a temperature, $T^*$, which is determined by the difference in energy between the Fermi level and the van Hove singularity. When vertex corrections are take"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1807.09683","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":"2026-05-18T00:02:31Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Ni/Ee6fJeZNn6ttRHvEa8Z70Ey8kceDVvWKpj5tpL/qhq1dEaMDshRRZTLLfAThaWeerpDIMIpdPhyVh1EB9Dw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-06T13:21:44.956421Z"},"content_sha256":"ff136f7f0a41980f4a23bcd6ed3ad7c782fadff7bf396c09d094e6e5f003747b","schema_version":"1.0","event_id":"sha256:ff136f7f0a41980f4a23bcd6ed3ad7c782fadff7bf396c09d094e6e5f003747b"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/R2I5VJOWJJXJID2ZAMX6IH7G7E/bundle.json","state_url":"https://pith.science/pith/R2I5VJOWJJXJID2ZAMX6IH7G7E/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/R2I5VJOWJJXJID2ZAMX6IH7G7E/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":"2026-06-06T13:21:44Z","links":{"resolver":"https://pith.science/pith/R2I5VJOWJJXJID2ZAMX6IH7G7E","bundle":"https://pith.science/pith/R2I5VJOWJJXJID2ZAMX6IH7G7E/bundle.json","state":"https://pith.science/pith/R2I5VJOWJJXJID2ZAMX6IH7G7E/state.json","well_known_bundle":"https://pith.science/.well-known/pith/R2I5VJOWJJXJID2ZAMX6IH7G7E/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:R2I5VJOWJJXJID2ZAMX6IH7G7E","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":"9d0a683b690305d04eee944d8423dc9ee0c3308a324f9c2cf31b4c5bc56b4bb3","cross_cats_sorted":["cond-mat.mtrl-sci","cond-mat.supr-con"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2018-07-25T16:01:09Z","title_canon_sha256":"69e366e5d5270e0fbf65e8ff19e022992e678df7a0e9d15d342a95481089ecc4"},"schema_version":"1.0","source":{"id":"1807.09683","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1807.09683","created_at":"2026-05-18T00:02:31Z"},{"alias_kind":"arxiv_version","alias_value":"1807.09683v1","created_at":"2026-05-18T00:02:31Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1807.09683","created_at":"2026-05-18T00:02:31Z"},{"alias_kind":"pith_short_12","alias_value":"R2I5VJOWJJXJ","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_16","alias_value":"R2I5VJOWJJXJID2Z","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_8","alias_value":"R2I5VJOW","created_at":"2026-05-18T12:32:50Z"}],"graph_snapshots":[{"event_id":"sha256:ff136f7f0a41980f4a23bcd6ed3ad7c782fadff7bf396c09d094e6e5f003747b","target":"graph","created_at":"2026-05-18T00:02:31Z","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 unconventional temperature variation of the Knight shift (static spin susceptibility) that has been observed in Fe-based superconductors AFe$_2$As$_2$ (A = K, Rb, Cs) is explained in terms of proximity to a van Hove singularity. Using the Hubbard model we show that when the Fermi energy is in the vicinity of a van Hove singularity, a downturn in spin susceptibility occurs as the temperature is lowered. This behavior is characterized by a temperature, $T^*$, which is determined by the difference in energy between the Fermi level and the van Hove singularity. When vertex corrections are take","authors_text":"R. Nourafkan, S. Acheche","cross_cats":["cond-mat.mtrl-sci","cond-mat.supr-con"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2018-07-25T16:01:09Z","title":"Temperature dependence of NMR Knight shift in pnictides: proximity to a van Hove singularity"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1807.09683","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":"sha256:23accc30e840ba8de42e1419647175cbea95ed3f472b6c498a7224a2f9013354","target":"record","created_at":"2026-05-18T00:02:31Z","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":"9d0a683b690305d04eee944d8423dc9ee0c3308a324f9c2cf31b4c5bc56b4bb3","cross_cats_sorted":["cond-mat.mtrl-sci","cond-mat.supr-con"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.str-el","submitted_at":"2018-07-25T16:01:09Z","title_canon_sha256":"69e366e5d5270e0fbf65e8ff19e022992e678df7a0e9d15d342a95481089ecc4"},"schema_version":"1.0","source":{"id":"1807.09683","kind":"arxiv","version":1}},"canonical_sha256":"8e91daa5d64a6e940f59032fe41fe6f911e069d0c7caed9c045888d378977ed4","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"8e91daa5d64a6e940f59032fe41fe6f911e069d0c7caed9c045888d378977ed4","first_computed_at":"2026-05-18T00:02:31.577245Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:02:31.577245Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"JjgT20JOB5jcqaibUZCzVkCV8bcGp4XrJF84anU7rJ94xAEP+wVpfjxllZccS/pO8SMdMamn9akJ87Oz1Vu4DA==","signature_status":"signed_v1","signed_at":"2026-05-18T00:02:31.577937Z","signed_message":"canonical_sha256_bytes"},"source_id":"1807.09683","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:23accc30e840ba8de42e1419647175cbea95ed3f472b6c498a7224a2f9013354","sha256:ff136f7f0a41980f4a23bcd6ed3ad7c782fadff7bf396c09d094e6e5f003747b"],"state_sha256":"3a2c9c4824bdb287f1bbee7333eb791559849076bb6c13acff7b56ba3a92f7a4"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"UyQZ8Tp4/JyM9c0FT64SimNRJHjM4RuzRcYJObKOwO99F9OHymrCsMUwckXhOaKOmoxu1h5FD6aVaJUzLpMhAQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-06T13:21:44.959839Z","bundle_sha256":"39feb5a7bd49d1d0d68ad650bcace1f5501a9265a041bd9984376d3817eaeb75"}}