{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2009:3AFKLDBNVY42EWN5ETESVCDP7N","short_pith_number":"pith:3AFKLDBN","canonical_record":{"source":{"id":"0901.4268","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2009-01-27T16:14:51Z","cross_cats_sorted":[],"title_canon_sha256":"3cf91a4ae3dded02a4b57ef3d3272dd70a21efd2a19f043ff91fe2fd3dd1ce29","abstract_canon_sha256":"e84121c852876592078741fd0dad18850df765b11996ca8c7c4411bafdc0b041"},"schema_version":"1.0"},"canonical_sha256":"d80aa58c2dae39a259bd24c92a886ffb692b8ce2abfe67be3ad7e027b8451f98","source":{"kind":"arxiv","id":"0901.4268","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0901.4268","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"arxiv_version","alias_value":"0901.4268v3","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0901.4268","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"pith_short_12","alias_value":"3AFKLDBNVY42","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_16","alias_value":"3AFKLDBNVY42EWN5","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_8","alias_value":"3AFKLDBN","created_at":"2026-05-18T12:25:58Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2009:3AFKLDBNVY42EWN5ETESVCDP7N","target":"record","payload":{"canonical_record":{"source":{"id":"0901.4268","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2009-01-27T16:14:51Z","cross_cats_sorted":[],"title_canon_sha256":"3cf91a4ae3dded02a4b57ef3d3272dd70a21efd2a19f043ff91fe2fd3dd1ce29","abstract_canon_sha256":"e84121c852876592078741fd0dad18850df765b11996ca8c7c4411bafdc0b041"},"schema_version":"1.0"},"canonical_sha256":"d80aa58c2dae39a259bd24c92a886ffb692b8ce2abfe67be3ad7e027b8451f98","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:14:55.645859Z","signature_b64":"LxVFe7SfnFKE3ceK6qSjtuvVjQBLo+jvf5BQ+qGoMjla6D7xaUS1QueOKs7bWuJqVeen3q4nJu953Szcw0RQDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"d80aa58c2dae39a259bd24c92a886ffb692b8ce2abfe67be3ad7e027b8451f98","last_reissued_at":"2026-05-18T02:14:55.645334Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:14:55.645334Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0901.4268","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T02:14:55Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"3QrcjrT3QJAxNe5d+ts6Od28rN8TwXmZN40A8lRgwlA3InXI1LxTF7ru9HesALa8wdwDSQhIyf2bwBAgRkjfDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T15:25:35.278015Z"},"content_sha256":"0db1937be9c7c4490f28999e16fa67a5d04ef36c93ab9800a9f1a64b6b986b26","schema_version":"1.0","event_id":"sha256:0db1937be9c7c4490f28999e16fa67a5d04ef36c93ab9800a9f1a64b6b986b26"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2009:3AFKLDBNVY42EWN5ETESVCDP7N","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Direct bandgap optical transitions in Si nanocrystals","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mtrl-sci","authors_text":"A. A. Prokofiev, A. S. Moskalenko, D. Timmerman, H. Zhang, I. N. Yassievich, T. Gregorkiewicz, W. D. A. M. de Boer, W. J. Buma","submitted_at":"2009-01-27T16:14:51Z","abstract_excerpt":"The effect of quantum confinement on the direct bandgap of spherical Si nanocrystals has been modelled theoretically. We conclude that the energy of the direct bandgap at the $\\Gamma$-point decreases with size reduction: quantum confinement enhances radiative recombination across the direct bandgap and introduces its \"red\" shift for smaller grains. We postulate to identify the frequently reported efficient blue emission (F-band) from Si nanocrystals with this zero-phonon recombination. In a dedicated experiment, we confirm the \"red\" shift of the F-band, supporting the proposed identification."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0901.4268","kind":"arxiv","version":3},"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":"2026-05-18T02:14:55Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"4HEfm/nJNPUDC9PJNIN6k6vUZcT4fM51qPoSAPvDBKsDA61IQHw0AlkL+nP+VAJLNpVBb7C5D0GJr/BBlYhZDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T15:25:35.278423Z"},"content_sha256":"e90e82db12eccc13fb83db483a85196a2e3c1c55c904526f14528da7aca18d60","schema_version":"1.0","event_id":"sha256:e90e82db12eccc13fb83db483a85196a2e3c1c55c904526f14528da7aca18d60"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/3AFKLDBNVY42EWN5ETESVCDP7N/bundle.json","state_url":"https://pith.science/pith/3AFKLDBNVY42EWN5ETESVCDP7N/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/3AFKLDBNVY42EWN5ETESVCDP7N/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":"2026-05-30T15:25:35Z","links":{"resolver":"https://pith.science/pith/3AFKLDBNVY42EWN5ETESVCDP7N","bundle":"https://pith.science/pith/3AFKLDBNVY42EWN5ETESVCDP7N/bundle.json","state":"https://pith.science/pith/3AFKLDBNVY42EWN5ETESVCDP7N/state.json","well_known_bundle":"https://pith.science/.well-known/pith/3AFKLDBNVY42EWN5ETESVCDP7N/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2009:3AFKLDBNVY42EWN5ETESVCDP7N","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":"e84121c852876592078741fd0dad18850df765b11996ca8c7c4411bafdc0b041","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2009-01-27T16:14:51Z","title_canon_sha256":"3cf91a4ae3dded02a4b57ef3d3272dd70a21efd2a19f043ff91fe2fd3dd1ce29"},"schema_version":"1.0","source":{"id":"0901.4268","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0901.4268","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"arxiv_version","alias_value":"0901.4268v3","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0901.4268","created_at":"2026-05-18T02:14:55Z"},{"alias_kind":"pith_short_12","alias_value":"3AFKLDBNVY42","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_16","alias_value":"3AFKLDBNVY42EWN5","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_8","alias_value":"3AFKLDBN","created_at":"2026-05-18T12:25:58Z"}],"graph_snapshots":[{"event_id":"sha256:e90e82db12eccc13fb83db483a85196a2e3c1c55c904526f14528da7aca18d60","target":"graph","created_at":"2026-05-18T02:14:55Z","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 effect of quantum confinement on the direct bandgap of spherical Si nanocrystals has been modelled theoretically. We conclude that the energy of the direct bandgap at the $\\Gamma$-point decreases with size reduction: quantum confinement enhances radiative recombination across the direct bandgap and introduces its \"red\" shift for smaller grains. We postulate to identify the frequently reported efficient blue emission (F-band) from Si nanocrystals with this zero-phonon recombination. In a dedicated experiment, we confirm the \"red\" shift of the F-band, supporting the proposed identification.","authors_text":"A. A. Prokofiev, A. S. Moskalenko, D. Timmerman, H. Zhang, I. N. Yassievich, T. Gregorkiewicz, W. D. A. M. de Boer, W. J. Buma","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2009-01-27T16:14:51Z","title":"Direct bandgap optical transitions in Si nanocrystals"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0901.4268","kind":"arxiv","version":3},"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":"sha256:0db1937be9c7c4490f28999e16fa67a5d04ef36c93ab9800a9f1a64b6b986b26","target":"record","created_at":"2026-05-18T02:14:55Z","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":"e84121c852876592078741fd0dad18850df765b11996ca8c7c4411bafdc0b041","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2009-01-27T16:14:51Z","title_canon_sha256":"3cf91a4ae3dded02a4b57ef3d3272dd70a21efd2a19f043ff91fe2fd3dd1ce29"},"schema_version":"1.0","source":{"id":"0901.4268","kind":"arxiv","version":3}},"canonical_sha256":"d80aa58c2dae39a259bd24c92a886ffb692b8ce2abfe67be3ad7e027b8451f98","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d80aa58c2dae39a259bd24c92a886ffb692b8ce2abfe67be3ad7e027b8451f98","first_computed_at":"2026-05-18T02:14:55.645334Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:14:55.645334Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"LxVFe7SfnFKE3ceK6qSjtuvVjQBLo+jvf5BQ+qGoMjla6D7xaUS1QueOKs7bWuJqVeen3q4nJu953Szcw0RQDg==","signature_status":"signed_v1","signed_at":"2026-05-18T02:14:55.645859Z","signed_message":"canonical_sha256_bytes"},"source_id":"0901.4268","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:0db1937be9c7c4490f28999e16fa67a5d04ef36c93ab9800a9f1a64b6b986b26","sha256:e90e82db12eccc13fb83db483a85196a2e3c1c55c904526f14528da7aca18d60"],"state_sha256":"1577bc64fa066568232f0ce03c3f1a70812000da32a5c2f4325c7ef9e56a45e6"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"MRyYWnVbP+we/FZ+iQOAtxYOZCZdrQzDtn29bUbwJCgxWiydZNV/EyGPQWjWAeEBCDbzw9zWByA/N8ugMg/yAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-30T15:25:35.280427Z","bundle_sha256":"f1041ff3d2dc3a5858420799daa155003a49049cf5106ad20ef37e958fe3499b"}}