{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2014:BQXXE7CJRSEWVLMWDCE4IPE3IM","short_pith_number":"pith:BQXXE7CJ","canonical_record":{"source":{"id":"1409.8662","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2014-09-30T19:26:06Z","cross_cats_sorted":[],"title_canon_sha256":"3f3398e24198e6490c626a3964876361a6518b5e03ae4ce35f075a0fd1789950","abstract_canon_sha256":"be056de243c4b32e8dd6d95ded92424674f44d1f2af0fda01c7d6e2b6d53ce41"},"schema_version":"1.0"},"canonical_sha256":"0c2f727c498c896aad961889c43c9b432b9e1c96fa031ca9572f5db287b93bdb","source":{"kind":"arxiv","id":"1409.8662","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1409.8662","created_at":"2026-05-18T02:41:19Z"},{"alias_kind":"arxiv_version","alias_value":"1409.8662v1","created_at":"2026-05-18T02:41:19Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1409.8662","created_at":"2026-05-18T02:41:19Z"},{"alias_kind":"pith_short_12","alias_value":"BQXXE7CJRSEW","created_at":"2026-05-18T12:28:22Z"},{"alias_kind":"pith_short_16","alias_value":"BQXXE7CJRSEWVLMW","created_at":"2026-05-18T12:28:22Z"},{"alias_kind":"pith_short_8","alias_value":"BQXXE7CJ","created_at":"2026-05-18T12:28:22Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2014:BQXXE7CJRSEWVLMWDCE4IPE3IM","target":"record","payload":{"canonical_record":{"source":{"id":"1409.8662","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2014-09-30T19:26:06Z","cross_cats_sorted":[],"title_canon_sha256":"3f3398e24198e6490c626a3964876361a6518b5e03ae4ce35f075a0fd1789950","abstract_canon_sha256":"be056de243c4b32e8dd6d95ded92424674f44d1f2af0fda01c7d6e2b6d53ce41"},"schema_version":"1.0"},"canonical_sha256":"0c2f727c498c896aad961889c43c9b432b9e1c96fa031ca9572f5db287b93bdb","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:41:19.084112Z","signature_b64":"oAp8qgwnEXg41vKG5XmbozNbiRZhmbiqz0cjA96zyRVoSU5qDz5k6qAVdZw0ArTsn/aJUN4AB8lpxHheS/h9BA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"0c2f727c498c896aad961889c43c9b432b9e1c96fa031ca9572f5db287b93bdb","last_reissued_at":"2026-05-18T02:41:19.083531Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:41:19.083531Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1409.8662","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":"2026-05-18T02:41:19Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Jja0KGd4Lzc7pU56i/LuC/BS2SYIW0mV2lGKUPcfOMduFHnf+0K4e78XJoi19ADbU/38xp5M+upyqxx57g5yBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T08:48:59.338765Z"},"content_sha256":"e157314395779af80030c9fbfa16df455efdc3d25dcfd24146540c0db3e848f6","schema_version":"1.0","event_id":"sha256:e157314395779af80030c9fbfa16df455efdc3d25dcfd24146540c0db3e848f6"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2014:BQXXE7CJRSEWVLMWDCE4IPE3IM","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Ultrafast exciton formation at the ZnO(10${\\overline{\\textbf{1}}}$0) surface","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mtrl-sci","authors_text":"C. Richter, D. Wegkamp, J.-C. Deinert, J. St\\\"ahler, M. Meyer, M. Wolf","submitted_at":"2014-09-30T19:26:06Z","abstract_excerpt":"We study the ultrafast quasiparticle dynamics in and below the ZnO conduction band using femtosecond time-resolved two-photon photoelectron spectroscopy. Above band gap excitation causes hot electron relaxation by electron-phonon scattering down to the Fermi level $E_\\text{F}$ followed by ultrafast (200 fs) formation of a surface exciton (SX). Transient screening of the Coulomb interaction reduces the SX formation probability at high excitation densities near the Mott limit. Located just below the surface, the SX are stable with regard to hydrogen-induced work function modifications and thus t"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1409.8662","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":"2026-05-18T02:41:19Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"q/xVJtXhSpduiCK0dbrnUT6LxoTg4kM/M4UG4KIFYsT0UQyc96/jzVMCTsUtZsm89e5cD85UWpx8cDW6i668Cw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T08:48:59.339109Z"},"content_sha256":"e0a6202ad424825d99f99f83f56bd740d90f080d6fb08b19c40783e4c4f7b01b","schema_version":"1.0","event_id":"sha256:e0a6202ad424825d99f99f83f56bd740d90f080d6fb08b19c40783e4c4f7b01b"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/BQXXE7CJRSEWVLMWDCE4IPE3IM/bundle.json","state_url":"https://pith.science/pith/BQXXE7CJRSEWVLMWDCE4IPE3IM/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/BQXXE7CJRSEWVLMWDCE4IPE3IM/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":"2026-05-30T08:48:59Z","links":{"resolver":"https://pith.science/pith/BQXXE7CJRSEWVLMWDCE4IPE3IM","bundle":"https://pith.science/pith/BQXXE7CJRSEWVLMWDCE4IPE3IM/bundle.json","state":"https://pith.science/pith/BQXXE7CJRSEWVLMWDCE4IPE3IM/state.json","well_known_bundle":"https://pith.science/.well-known/pith/BQXXE7CJRSEWVLMWDCE4IPE3IM/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2014:BQXXE7CJRSEWVLMWDCE4IPE3IM","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":"be056de243c4b32e8dd6d95ded92424674f44d1f2af0fda01c7d6e2b6d53ce41","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2014-09-30T19:26:06Z","title_canon_sha256":"3f3398e24198e6490c626a3964876361a6518b5e03ae4ce35f075a0fd1789950"},"schema_version":"1.0","source":{"id":"1409.8662","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1409.8662","created_at":"2026-05-18T02:41:19Z"},{"alias_kind":"arxiv_version","alias_value":"1409.8662v1","created_at":"2026-05-18T02:41:19Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1409.8662","created_at":"2026-05-18T02:41:19Z"},{"alias_kind":"pith_short_12","alias_value":"BQXXE7CJRSEW","created_at":"2026-05-18T12:28:22Z"},{"alias_kind":"pith_short_16","alias_value":"BQXXE7CJRSEWVLMW","created_at":"2026-05-18T12:28:22Z"},{"alias_kind":"pith_short_8","alias_value":"BQXXE7CJ","created_at":"2026-05-18T12:28:22Z"}],"graph_snapshots":[{"event_id":"sha256:e0a6202ad424825d99f99f83f56bd740d90f080d6fb08b19c40783e4c4f7b01b","target":"graph","created_at":"2026-05-18T02:41:19Z","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 study the ultrafast quasiparticle dynamics in and below the ZnO conduction band using femtosecond time-resolved two-photon photoelectron spectroscopy. Above band gap excitation causes hot electron relaxation by electron-phonon scattering down to the Fermi level $E_\\text{F}$ followed by ultrafast (200 fs) formation of a surface exciton (SX). Transient screening of the Coulomb interaction reduces the SX formation probability at high excitation densities near the Mott limit. Located just below the surface, the SX are stable with regard to hydrogen-induced work function modifications and thus t","authors_text":"C. Richter, D. Wegkamp, J.-C. Deinert, J. St\\\"ahler, M. Meyer, M. Wolf","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2014-09-30T19:26:06Z","title":"Ultrafast exciton formation at the ZnO(10${\\overline{\\textbf{1}}}$0) surface"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1409.8662","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:e157314395779af80030c9fbfa16df455efdc3d25dcfd24146540c0db3e848f6","target":"record","created_at":"2026-05-18T02:41:19Z","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":"be056de243c4b32e8dd6d95ded92424674f44d1f2af0fda01c7d6e2b6d53ce41","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2014-09-30T19:26:06Z","title_canon_sha256":"3f3398e24198e6490c626a3964876361a6518b5e03ae4ce35f075a0fd1789950"},"schema_version":"1.0","source":{"id":"1409.8662","kind":"arxiv","version":1}},"canonical_sha256":"0c2f727c498c896aad961889c43c9b432b9e1c96fa031ca9572f5db287b93bdb","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"0c2f727c498c896aad961889c43c9b432b9e1c96fa031ca9572f5db287b93bdb","first_computed_at":"2026-05-18T02:41:19.083531Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:41:19.083531Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"oAp8qgwnEXg41vKG5XmbozNbiRZhmbiqz0cjA96zyRVoSU5qDz5k6qAVdZw0ArTsn/aJUN4AB8lpxHheS/h9BA==","signature_status":"signed_v1","signed_at":"2026-05-18T02:41:19.084112Z","signed_message":"canonical_sha256_bytes"},"source_id":"1409.8662","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e157314395779af80030c9fbfa16df455efdc3d25dcfd24146540c0db3e848f6","sha256:e0a6202ad424825d99f99f83f56bd740d90f080d6fb08b19c40783e4c4f7b01b"],"state_sha256":"133827c3af758f3254661238e4d470db8fe84105fa7957b02baf83de98daf875"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"zNpwxzsnH9huo80nfHSVqT+yW6P6LqOF+SXk9wx+4DYZ1XV3ugyyhFgoTwE+7mBUZIl4V2w9Cezpq+7mgNU0AQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-30T08:48:59.341224Z","bundle_sha256":"a5d4ac95b4b91152555a335f38e9debc15d15a54210facfef8a3843ac40256fc"}}