{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2014:36JOLOAGCSBHV7BDNRTPSCZRPU","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":"15449b92a6fedf0f374c30477da82339af473951ed526722cb0434481276573f","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2014-11-24T00:25:00Z","title_canon_sha256":"ed4eecb84b12aab430f457c710ec68582f5c962f69d7966f307dd0841e045874"},"schema_version":"1.0","source":{"id":"1411.6315","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1411.6315","created_at":"2026-05-18T02:28:47Z"},{"alias_kind":"arxiv_version","alias_value":"1411.6315v1","created_at":"2026-05-18T02:28:47Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1411.6315","created_at":"2026-05-18T02:28:47Z"},{"alias_kind":"pith_short_12","alias_value":"36JOLOAGCSBH","created_at":"2026-05-18T12:28:11Z"},{"alias_kind":"pith_short_16","alias_value":"36JOLOAGCSBHV7BD","created_at":"2026-05-18T12:28:11Z"},{"alias_kind":"pith_short_8","alias_value":"36JOLOAG","created_at":"2026-05-18T12:28:11Z"}],"graph_snapshots":[{"event_id":"sha256:d377be9697f4bb969781644e48bdbfec5567045c440544f5dea62ee600ce088b","target":"graph","created_at":"2026-05-18T02:28:47Z","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":"Standing on successful first principles predictions for new functional ferroelectric materials, a number of new ferroelectrics have been experimentally discovered. Utilizing trilinear coupling of two types of octahedron rotations, hybrid improper ferroelectricity has been theoretically predicted in ordered perovskites and the Ruddlesden-Popper compounds (Ca$_{3}$Ti$_{2}$O$_{7}$, Ca$_{3}$Mn$_{2}$O$_{7}$, and (Ca/Sr/Ba)$_{3}$(Sn/Zr/Ge)$_{2}$O$_{7}$). However, the ferroelectricity of these compounds has never been experimentally confirmed and even their polar nature has been under debate. Here we","authors_text":"Fei-Ting Huang, Sang-Wook Cheong, Xuan Luo, Yazhong Wang, Yoon Seok Oh","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2014-11-24T00:25:00Z","title":"Experimental demonstration of hybrid improper ferroelectricity and presence of abundant charged walls in (Ca,Sr)$_{3}$Ti$_{2}$O$_{7}$ crystals"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1411.6315","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":"sha256:28e950e44b01c580e6f79a0e3257fa1987b2b7216b3a15fd841f18dd6d62af46","target":"record","created_at":"2026-05-18T02:28:47Z","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":"15449b92a6fedf0f374c30477da82339af473951ed526722cb0434481276573f","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2014-11-24T00:25:00Z","title_canon_sha256":"ed4eecb84b12aab430f457c710ec68582f5c962f69d7966f307dd0841e045874"},"schema_version":"1.0","source":{"id":"1411.6315","kind":"arxiv","version":1}},"canonical_sha256":"df92e5b80614827afc236c66f90b317d371bbfd99232480a7a75fa822e86f250","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"df92e5b80614827afc236c66f90b317d371bbfd99232480a7a75fa822e86f250","first_computed_at":"2026-05-18T02:28:47.430701Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:28:47.430701Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Jof6T2xhuqMeH1fB2895/eLXJPxXyhHYDpEmEIpk6SjYFeVa5Fato0PsUkPBCxQHgqOS2fdv+2rAnAOg1FfGAw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:28:47.431217Z","signed_message":"canonical_sha256_bytes"},"source_id":"1411.6315","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:28e950e44b01c580e6f79a0e3257fa1987b2b7216b3a15fd841f18dd6d62af46","sha256:d377be9697f4bb969781644e48bdbfec5567045c440544f5dea62ee600ce088b"],"state_sha256":"e133384a9e875d91b484f4b6f5be80cb8ed9fc828f6a4f2333b5510fd81fca3c"}