{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:EIXKEP5F2LH2AJE7A72B57TA3F","short_pith_number":"pith:EIXKEP5F","canonical_record":{"source":{"id":"2110.09728","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2021-10-19T04:30:14Z","cross_cats_sorted":[],"title_canon_sha256":"babcd3b69ac7e3c50cb263662b928ff3281679a64003d3453bcf0498f53fedbf","abstract_canon_sha256":"9a650e89b7fd2d63192848fe3163f6c0d7a990d0d68f71cf751d00860fd3e6fa"},"schema_version":"1.0"},"canonical_sha256":"222ea23fa5d2cfa0249f07f41efe60d95256ed228ec779b136672b18fd3bcad5","source":{"kind":"arxiv","id":"2110.09728","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2110.09728","created_at":"2026-07-05T03:23:58Z"},{"alias_kind":"arxiv_version","alias_value":"2110.09728v1","created_at":"2026-07-05T03:23:58Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2110.09728","created_at":"2026-07-05T03:23:58Z"},{"alias_kind":"pith_short_12","alias_value":"EIXKEP5F2LH2","created_at":"2026-07-05T03:23:58Z"},{"alias_kind":"pith_short_16","alias_value":"EIXKEP5F2LH2AJE7","created_at":"2026-07-05T03:23:58Z"},{"alias_kind":"pith_short_8","alias_value":"EIXKEP5F","created_at":"2026-07-05T03:23:58Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:EIXKEP5F2LH2AJE7A72B57TA3F","target":"record","payload":{"canonical_record":{"source":{"id":"2110.09728","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2021-10-19T04:30:14Z","cross_cats_sorted":[],"title_canon_sha256":"babcd3b69ac7e3c50cb263662b928ff3281679a64003d3453bcf0498f53fedbf","abstract_canon_sha256":"9a650e89b7fd2d63192848fe3163f6c0d7a990d0d68f71cf751d00860fd3e6fa"},"schema_version":"1.0"},"canonical_sha256":"222ea23fa5d2cfa0249f07f41efe60d95256ed228ec779b136672b18fd3bcad5","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T03:23:58.399157Z","signature_b64":"j0ji/LX7sgxAO0xmEt2OimhmiZVjNTgQnVUVz91x8MuZVWSSwaThQ9lATRuJNgWMKWdmQeMAjFZHkDN+a8dLBQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"222ea23fa5d2cfa0249f07f41efe60d95256ed228ec779b136672b18fd3bcad5","last_reissued_at":"2026-07-05T03:23:58.398736Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T03:23:58.398736Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2110.09728","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":"2026-07-05T03:23:58Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"faNXsvNNuMZ99CbSU9FKNJpEIWp64f6T+L4lJsBV99PNyGxHUjmdvwli657Xyy2n5xKUhbu85g+QCK/9NaHCCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-03T19:42:19.038326Z"},"content_sha256":"a22a409a3199bd359d5e2ac2999d672c1aba3df6b96c2ab5660e2c6e8df0a77e","schema_version":"1.0","event_id":"sha256:a22a409a3199bd359d5e2ac2999d672c1aba3df6b96c2ab5660e2c6e8df0a77e"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:EIXKEP5F2LH2AJE7A72B57TA3F","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Ultrafast generation and detection of propagating coherent acoustic phonon wave packets in ultra-thin iron pnictide films","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mtrl-sci","authors_text":"B. Song, C. B. Eom, C. Sundahl, D. Cheng, E. E. Hellstrom, I. E. Perakis, J. H. Kang, J-M. Park, J. Wang, L. Luo, M. Mootz, Y. G. Collantes","submitted_at":"2021-10-19T04:30:14Z","abstract_excerpt":"We observe pronounced oscillations in differential reflectivity of 9 nm and 60 nm BaFe\\textsubscript{2}As\\textsubscript{2} (Ba-122) thin films using ultrafast optical spectroscopy. Our studies show that the oscillations result from propagating longitudinal acoustic (LA) phonon wave packets with strong thickness and temperature dependence. Particularly, the experimentally measured oscillation frequency approaches to 50 GHz for the ultra-thin film. Our calculations show that Young's modulus of 9 nm thin film is nearly four times as large as that of 60 nm thin film, consistent with the experiment"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2110.09728","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2110.09728/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2026-07-05T03:23:58Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Zw+L7lx0RdZOk+ri8ibBNaR5b732KP0sHbRXLeJO09vAD9NFucqvOJDUzhT3zRtUiEqJ74GRfkHjnTel/lVCCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-03T19:42:19.039774Z"},"content_sha256":"ae62549bbd2d898d3c4c81da6bde80b3d36583eef61053212eca6c90af88eda2","schema_version":"1.0","event_id":"sha256:ae62549bbd2d898d3c4c81da6bde80b3d36583eef61053212eca6c90af88eda2"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/EIXKEP5F2LH2AJE7A72B57TA3F/bundle.json","state_url":"https://pith.science/pith/EIXKEP5F2LH2AJE7A72B57TA3F/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/EIXKEP5F2LH2AJE7A72B57TA3F/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":"2026-08-03T19:42:19Z","links":{"resolver":"https://pith.science/pith/EIXKEP5F2LH2AJE7A72B57TA3F","bundle":"https://pith.science/pith/EIXKEP5F2LH2AJE7A72B57TA3F/bundle.json","state":"https://pith.science/pith/EIXKEP5F2LH2AJE7A72B57TA3F/state.json","well_known_bundle":"https://pith.science/.well-known/pith/EIXKEP5F2LH2AJE7A72B57TA3F/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:EIXKEP5F2LH2AJE7A72B57TA3F","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":"9a650e89b7fd2d63192848fe3163f6c0d7a990d0d68f71cf751d00860fd3e6fa","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2021-10-19T04:30:14Z","title_canon_sha256":"babcd3b69ac7e3c50cb263662b928ff3281679a64003d3453bcf0498f53fedbf"},"schema_version":"1.0","source":{"id":"2110.09728","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2110.09728","created_at":"2026-07-05T03:23:58Z"},{"alias_kind":"arxiv_version","alias_value":"2110.09728v1","created_at":"2026-07-05T03:23:58Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2110.09728","created_at":"2026-07-05T03:23:58Z"},{"alias_kind":"pith_short_12","alias_value":"EIXKEP5F2LH2","created_at":"2026-07-05T03:23:58Z"},{"alias_kind":"pith_short_16","alias_value":"EIXKEP5F2LH2AJE7","created_at":"2026-07-05T03:23:58Z"},{"alias_kind":"pith_short_8","alias_value":"EIXKEP5F","created_at":"2026-07-05T03:23:58Z"}],"graph_snapshots":[{"event_id":"sha256:ae62549bbd2d898d3c4c81da6bde80b3d36583eef61053212eca6c90af88eda2","target":"graph","created_at":"2026-07-05T03:23:58Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2110.09728/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We observe pronounced oscillations in differential reflectivity of 9 nm and 60 nm BaFe\\textsubscript{2}As\\textsubscript{2} (Ba-122) thin films using ultrafast optical spectroscopy. Our studies show that the oscillations result from propagating longitudinal acoustic (LA) phonon wave packets with strong thickness and temperature dependence. Particularly, the experimentally measured oscillation frequency approaches to 50 GHz for the ultra-thin film. Our calculations show that Young's modulus of 9 nm thin film is nearly four times as large as that of 60 nm thin film, consistent with the experiment","authors_text":"B. Song, C. B. Eom, C. Sundahl, D. Cheng, E. E. Hellstrom, I. E. Perakis, J. H. Kang, J-M. Park, J. Wang, L. Luo, M. Mootz, Y. G. Collantes","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2021-10-19T04:30:14Z","title":"Ultrafast generation and detection of propagating coherent acoustic phonon wave packets in ultra-thin iron pnictide films"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2110.09728","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:a22a409a3199bd359d5e2ac2999d672c1aba3df6b96c2ab5660e2c6e8df0a77e","target":"record","created_at":"2026-07-05T03:23:58Z","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":"9a650e89b7fd2d63192848fe3163f6c0d7a990d0d68f71cf751d00860fd3e6fa","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2021-10-19T04:30:14Z","title_canon_sha256":"babcd3b69ac7e3c50cb263662b928ff3281679a64003d3453bcf0498f53fedbf"},"schema_version":"1.0","source":{"id":"2110.09728","kind":"arxiv","version":1}},"canonical_sha256":"222ea23fa5d2cfa0249f07f41efe60d95256ed228ec779b136672b18fd3bcad5","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"222ea23fa5d2cfa0249f07f41efe60d95256ed228ec779b136672b18fd3bcad5","first_computed_at":"2026-07-05T03:23:58.398736Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T03:23:58.398736Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"j0ji/LX7sgxAO0xmEt2OimhmiZVjNTgQnVUVz91x8MuZVWSSwaThQ9lATRuJNgWMKWdmQeMAjFZHkDN+a8dLBQ==","signature_status":"signed_v1","signed_at":"2026-07-05T03:23:58.399157Z","signed_message":"canonical_sha256_bytes"},"source_id":"2110.09728","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:a22a409a3199bd359d5e2ac2999d672c1aba3df6b96c2ab5660e2c6e8df0a77e","sha256:ae62549bbd2d898d3c4c81da6bde80b3d36583eef61053212eca6c90af88eda2"],"state_sha256":"f6cd66688c96c64a288a50a8c8e2e95813fec3a83fcf526c8b0bea44e938131e"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"gzXuRzP3bFZmGcHkViV/bWteNo3PNMQhfPxia0WPUBqC0tGtoMYpD1sooWv+aDJrmiHlohwv+0AnoK5iguzaCQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-03T19:42:19.045735Z","bundle_sha256":"ee7d08c63ccfa8f91220bb1a08c976082ea26163567cfc76719730290cf152af"}}