{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:4KLZCEDZTOEVTYHITQKLX2BXGF","short_pith_number":"pith:4KLZCEDZ","canonical_record":{"source":{"id":"1804.09492","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2018-04-25T11:55:56Z","cross_cats_sorted":[],"title_canon_sha256":"7dca602584c1d72e610085feab01e0f4520427a747abd3c79e3dfe5ba91590f5","abstract_canon_sha256":"f06018615f9d975c06db24d369886aed094ba1bc9af15796b1b03fa1f999cf3e"},"schema_version":"1.0"},"canonical_sha256":"e2979110799b8959e0e89c14bbe83731669476b9e16bbd0761ce0904ef483d64","source":{"kind":"arxiv","id":"1804.09492","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1804.09492","created_at":"2026-05-18T00:17:26Z"},{"alias_kind":"arxiv_version","alias_value":"1804.09492v2","created_at":"2026-05-18T00:17:26Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1804.09492","created_at":"2026-05-18T00:17:26Z"},{"alias_kind":"pith_short_12","alias_value":"4KLZCEDZTOEV","created_at":"2026-05-18T12:32:05Z"},{"alias_kind":"pith_short_16","alias_value":"4KLZCEDZTOEVTYHI","created_at":"2026-05-18T12:32:05Z"},{"alias_kind":"pith_short_8","alias_value":"4KLZCEDZ","created_at":"2026-05-18T12:32:05Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:4KLZCEDZTOEVTYHITQKLX2BXGF","target":"record","payload":{"canonical_record":{"source":{"id":"1804.09492","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2018-04-25T11:55:56Z","cross_cats_sorted":[],"title_canon_sha256":"7dca602584c1d72e610085feab01e0f4520427a747abd3c79e3dfe5ba91590f5","abstract_canon_sha256":"f06018615f9d975c06db24d369886aed094ba1bc9af15796b1b03fa1f999cf3e"},"schema_version":"1.0"},"canonical_sha256":"e2979110799b8959e0e89c14bbe83731669476b9e16bbd0761ce0904ef483d64","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:17:26.786616Z","signature_b64":"S7cf4RMmjPa2wCOsGOZjRQiSK8sG1VeXAJtogChpFgRwOZLL3ydDQF+UJfGZjYkICTh87EJZEszgEY6ZEBfDBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"e2979110799b8959e0e89c14bbe83731669476b9e16bbd0761ce0904ef483d64","last_reissued_at":"2026-05-18T00:17:26.785845Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:17:26.785845Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1804.09492","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":"2026-05-18T00:17:26Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"8V9Gu/J39kb8xPYIyak5RV9ZCxAcZpwCc6pG3PPfBWbAPJPheFEk9GbYr0kIzJxQwIuZE7l4b76Ag8/rQzdbDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T23:23:12.829967Z"},"content_sha256":"0cea8c7f3a91ebfffa062f9905efed9b48c302f5f2af42d6309da9fd8b907f32","schema_version":"1.0","event_id":"sha256:0cea8c7f3a91ebfffa062f9905efed9b48c302f5f2af42d6309da9fd8b907f32"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:4KLZCEDZTOEVTYHITQKLX2BXGF","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Surface and interface structure of quasi-free standing graphene on SiC","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mtrl-sci","authors_text":"Alex Shard, Christos Melios, Olga Kazakova, S. Ravi P. Silva, Steve Spencer, Wlodek Strupinski","submitted_at":"2018-04-25T11:55:56Z","abstract_excerpt":"We perform local nanoscale studies of the surface and interface structure of hydrogen intercalated graphene on 4H-SiC(1000). In particular, we show that intercalation of the interfacial layer results in the formation of quasi-free standing one layer graphene (QFS 1LG) with change in the carrier type from n- to p-type, accompanied by a more than four times increase in carrier mobility. We demonstrate that surface enhanced Raman scattering (SERS) reveals the enhanced Raman signal of Si-H stretching mode, which is the direct proof of successful intercalation. Furthermore, the appearance of D, D+D"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1804.09492","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":"2026-05-18T00:17:26Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"T/DrfA8zNudgcdJ71ISfRb6XwHt3t7ldj9qRL9RnnR90JVhd6l95VwCyNrnmZrEpAG+rnWoY/WyilmBE8q1ZAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T23:23:12.830337Z"},"content_sha256":"2ab062d6f44a9f5433cb07601069683d5383dfb5f80d343bf5685f76a2e41059","schema_version":"1.0","event_id":"sha256:2ab062d6f44a9f5433cb07601069683d5383dfb5f80d343bf5685f76a2e41059"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/4KLZCEDZTOEVTYHITQKLX2BXGF/bundle.json","state_url":"https://pith.science/pith/4KLZCEDZTOEVTYHITQKLX2BXGF/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/4KLZCEDZTOEVTYHITQKLX2BXGF/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":"2026-05-31T23:23:12Z","links":{"resolver":"https://pith.science/pith/4KLZCEDZTOEVTYHITQKLX2BXGF","bundle":"https://pith.science/pith/4KLZCEDZTOEVTYHITQKLX2BXGF/bundle.json","state":"https://pith.science/pith/4KLZCEDZTOEVTYHITQKLX2BXGF/state.json","well_known_bundle":"https://pith.science/.well-known/pith/4KLZCEDZTOEVTYHITQKLX2BXGF/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:4KLZCEDZTOEVTYHITQKLX2BXGF","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":"f06018615f9d975c06db24d369886aed094ba1bc9af15796b1b03fa1f999cf3e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2018-04-25T11:55:56Z","title_canon_sha256":"7dca602584c1d72e610085feab01e0f4520427a747abd3c79e3dfe5ba91590f5"},"schema_version":"1.0","source":{"id":"1804.09492","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1804.09492","created_at":"2026-05-18T00:17:26Z"},{"alias_kind":"arxiv_version","alias_value":"1804.09492v2","created_at":"2026-05-18T00:17:26Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1804.09492","created_at":"2026-05-18T00:17:26Z"},{"alias_kind":"pith_short_12","alias_value":"4KLZCEDZTOEV","created_at":"2026-05-18T12:32:05Z"},{"alias_kind":"pith_short_16","alias_value":"4KLZCEDZTOEVTYHI","created_at":"2026-05-18T12:32:05Z"},{"alias_kind":"pith_short_8","alias_value":"4KLZCEDZ","created_at":"2026-05-18T12:32:05Z"}],"graph_snapshots":[{"event_id":"sha256:2ab062d6f44a9f5433cb07601069683d5383dfb5f80d343bf5685f76a2e41059","target":"graph","created_at":"2026-05-18T00:17:26Z","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 perform local nanoscale studies of the surface and interface structure of hydrogen intercalated graphene on 4H-SiC(1000). In particular, we show that intercalation of the interfacial layer results in the formation of quasi-free standing one layer graphene (QFS 1LG) with change in the carrier type from n- to p-type, accompanied by a more than four times increase in carrier mobility. We demonstrate that surface enhanced Raman scattering (SERS) reveals the enhanced Raman signal of Si-H stretching mode, which is the direct proof of successful intercalation. Furthermore, the appearance of D, D+D","authors_text":"Alex Shard, Christos Melios, Olga Kazakova, S. Ravi P. Silva, Steve Spencer, Wlodek Strupinski","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2018-04-25T11:55:56Z","title":"Surface and interface structure of quasi-free standing graphene on SiC"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1804.09492","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":"sha256:0cea8c7f3a91ebfffa062f9905efed9b48c302f5f2af42d6309da9fd8b907f32","target":"record","created_at":"2026-05-18T00:17:26Z","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":"f06018615f9d975c06db24d369886aed094ba1bc9af15796b1b03fa1f999cf3e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2018-04-25T11:55:56Z","title_canon_sha256":"7dca602584c1d72e610085feab01e0f4520427a747abd3c79e3dfe5ba91590f5"},"schema_version":"1.0","source":{"id":"1804.09492","kind":"arxiv","version":2}},"canonical_sha256":"e2979110799b8959e0e89c14bbe83731669476b9e16bbd0761ce0904ef483d64","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"e2979110799b8959e0e89c14bbe83731669476b9e16bbd0761ce0904ef483d64","first_computed_at":"2026-05-18T00:17:26.785845Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:17:26.785845Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"S7cf4RMmjPa2wCOsGOZjRQiSK8sG1VeXAJtogChpFgRwOZLL3ydDQF+UJfGZjYkICTh87EJZEszgEY6ZEBfDBw==","signature_status":"signed_v1","signed_at":"2026-05-18T00:17:26.786616Z","signed_message":"canonical_sha256_bytes"},"source_id":"1804.09492","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:0cea8c7f3a91ebfffa062f9905efed9b48c302f5f2af42d6309da9fd8b907f32","sha256:2ab062d6f44a9f5433cb07601069683d5383dfb5f80d343bf5685f76a2e41059"],"state_sha256":"26b270780ee79059421c3aac37df910f5d14fdf7015b8bac6fba1e1ce2c6c9d0"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"dt4GXnGW6iAebgDwlKXUCsP0cVQgnfuZre3oJ/MDpEJX33anEv9+cD9FZUtgV2n6o7STdIlUqFKxONz8IqL2Dw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-31T23:23:12.832442Z","bundle_sha256":"b6c1c8c4d91c43e80df782603dc416206f39135012e088d8f11fb5e74f29f78c"}}