{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2017:OZ7SVL6ONYJQQ5HKVHRQI42FXA","short_pith_number":"pith:OZ7SVL6O","canonical_record":{"source":{"id":"1703.01019","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2017-03-03T03:02:17Z","cross_cats_sorted":[],"title_canon_sha256":"095fd0a536089da238f03e11184b8a57751492e69e574b58398427cbb8d280a7","abstract_canon_sha256":"404b1f5bab42bdcf66c0842f73901393a3cd8f5f091dd8c60efcc84770d02d75"},"schema_version":"1.0"},"canonical_sha256":"767f2aafce6e130874eaa9e3047345b830167449f0ef72cd8e646790874ed274","source":{"kind":"arxiv","id":"1703.01019","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1703.01019","created_at":"2026-05-18T00:43:54Z"},{"alias_kind":"arxiv_version","alias_value":"1703.01019v1","created_at":"2026-05-18T00:43:54Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1703.01019","created_at":"2026-05-18T00:43:54Z"},{"alias_kind":"pith_short_12","alias_value":"OZ7SVL6ONYJQ","created_at":"2026-05-18T12:31:34Z"},{"alias_kind":"pith_short_16","alias_value":"OZ7SVL6ONYJQQ5HK","created_at":"2026-05-18T12:31:34Z"},{"alias_kind":"pith_short_8","alias_value":"OZ7SVL6O","created_at":"2026-05-18T12:31:34Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2017:OZ7SVL6ONYJQQ5HKVHRQI42FXA","target":"record","payload":{"canonical_record":{"source":{"id":"1703.01019","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2017-03-03T03:02:17Z","cross_cats_sorted":[],"title_canon_sha256":"095fd0a536089da238f03e11184b8a57751492e69e574b58398427cbb8d280a7","abstract_canon_sha256":"404b1f5bab42bdcf66c0842f73901393a3cd8f5f091dd8c60efcc84770d02d75"},"schema_version":"1.0"},"canonical_sha256":"767f2aafce6e130874eaa9e3047345b830167449f0ef72cd8e646790874ed274","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:43:54.011546Z","signature_b64":"n1qJgg/zPxvEpExjhwrbuikbQn4TkUUHq1DD99Q7DTbv1gl0j5rHdxw7GfG3n1PCYqPnaKe1qqX0TfPBGBUjDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"767f2aafce6e130874eaa9e3047345b830167449f0ef72cd8e646790874ed274","last_reissued_at":"2026-05-18T00:43:54.011029Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:43:54.011029Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1703.01019","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":"2026-05-18T00:43:54Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"YoFSNAEkD2xK5i2U1p1J9TAFXTg1Znx7SPIclUB7fll1xgvHpQOTVWqhOYfDEFekPu8bu7D9QGv+D321xUXTDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-06T19:39:49.665131Z"},"content_sha256":"39c03094e6cf36408d7c2289561193ead856c137110f3121971c1cfc3dfdbfa6","schema_version":"1.0","event_id":"sha256:39c03094e6cf36408d7c2289561193ead856c137110f3121971c1cfc3dfdbfa6"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2017:OZ7SVL6ONYJQQ5HKVHRQI42FXA","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Optical evidence of blue shift in topological insulator bismuth selenide in the few-layer limit","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.mtrl-sci","authors_text":"Aaron Walber, Asma Alkabsh, Dipanjan Mazumdar, Hassana Samassekou, Yub Raj Sapkota","submitted_at":"2017-03-03T03:02:17Z","abstract_excerpt":"Optical band gap properties of high-quality few-layer topological insulator Bi2Se3 thin films grown with magnetron sputtering are investigated using broadband absorption spectroscopy. We provide direct optical evidence of a rigid blue-shift to up to 0.5 eV in the band gap of Bi2Se3 as it approaches the two-dimensional limit. The onset of this behavior is most significant below six quintuple layers. The blue shift is very robust and is observed in both protected (capped) and exposed (uncapped) thin films. Our results are consistent with observations that finite-size effects have profound impact"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1703.01019","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":"2026-05-18T00:43:54Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"YDC5HRY0Y941SCBr7oaVei/+ShADwaaybufF2etnte27U6gl+gcsHTkEaTWvXjT4KewdXjI0YDnd1lGXbwSKAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-06T19:39:49.665832Z"},"content_sha256":"260736427d3062ecf3a11fba6c8324a7cb24af45f42fedc0f3419499dddc1444","schema_version":"1.0","event_id":"sha256:260736427d3062ecf3a11fba6c8324a7cb24af45f42fedc0f3419499dddc1444"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/OZ7SVL6ONYJQQ5HKVHRQI42FXA/bundle.json","state_url":"https://pith.science/pith/OZ7SVL6ONYJQQ5HKVHRQI42FXA/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/OZ7SVL6ONYJQQ5HKVHRQI42FXA/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":"2026-06-06T19:39:49Z","links":{"resolver":"https://pith.science/pith/OZ7SVL6ONYJQQ5HKVHRQI42FXA","bundle":"https://pith.science/pith/OZ7SVL6ONYJQQ5HKVHRQI42FXA/bundle.json","state":"https://pith.science/pith/OZ7SVL6ONYJQQ5HKVHRQI42FXA/state.json","well_known_bundle":"https://pith.science/.well-known/pith/OZ7SVL6ONYJQQ5HKVHRQI42FXA/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2017:OZ7SVL6ONYJQQ5HKVHRQI42FXA","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":"404b1f5bab42bdcf66c0842f73901393a3cd8f5f091dd8c60efcc84770d02d75","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2017-03-03T03:02:17Z","title_canon_sha256":"095fd0a536089da238f03e11184b8a57751492e69e574b58398427cbb8d280a7"},"schema_version":"1.0","source":{"id":"1703.01019","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1703.01019","created_at":"2026-05-18T00:43:54Z"},{"alias_kind":"arxiv_version","alias_value":"1703.01019v1","created_at":"2026-05-18T00:43:54Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1703.01019","created_at":"2026-05-18T00:43:54Z"},{"alias_kind":"pith_short_12","alias_value":"OZ7SVL6ONYJQ","created_at":"2026-05-18T12:31:34Z"},{"alias_kind":"pith_short_16","alias_value":"OZ7SVL6ONYJQQ5HK","created_at":"2026-05-18T12:31:34Z"},{"alias_kind":"pith_short_8","alias_value":"OZ7SVL6O","created_at":"2026-05-18T12:31:34Z"}],"graph_snapshots":[{"event_id":"sha256:260736427d3062ecf3a11fba6c8324a7cb24af45f42fedc0f3419499dddc1444","target":"graph","created_at":"2026-05-18T00:43:54Z","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":"Optical band gap properties of high-quality few-layer topological insulator Bi2Se3 thin films grown with magnetron sputtering are investigated using broadband absorption spectroscopy. We provide direct optical evidence of a rigid blue-shift to up to 0.5 eV in the band gap of Bi2Se3 as it approaches the two-dimensional limit. The onset of this behavior is most significant below six quintuple layers. The blue shift is very robust and is observed in both protected (capped) and exposed (uncapped) thin films. Our results are consistent with observations that finite-size effects have profound impact","authors_text":"Aaron Walber, Asma Alkabsh, Dipanjan Mazumdar, Hassana Samassekou, Yub Raj Sapkota","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2017-03-03T03:02:17Z","title":"Optical evidence of blue shift in topological insulator bismuth selenide in the few-layer limit"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1703.01019","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":"sha256:39c03094e6cf36408d7c2289561193ead856c137110f3121971c1cfc3dfdbfa6","target":"record","created_at":"2026-05-18T00:43:54Z","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":"404b1f5bab42bdcf66c0842f73901393a3cd8f5f091dd8c60efcc84770d02d75","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2017-03-03T03:02:17Z","title_canon_sha256":"095fd0a536089da238f03e11184b8a57751492e69e574b58398427cbb8d280a7"},"schema_version":"1.0","source":{"id":"1703.01019","kind":"arxiv","version":1}},"canonical_sha256":"767f2aafce6e130874eaa9e3047345b830167449f0ef72cd8e646790874ed274","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"767f2aafce6e130874eaa9e3047345b830167449f0ef72cd8e646790874ed274","first_computed_at":"2026-05-18T00:43:54.011029Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:43:54.011029Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"n1qJgg/zPxvEpExjhwrbuikbQn4TkUUHq1DD99Q7DTbv1gl0j5rHdxw7GfG3n1PCYqPnaKe1qqX0TfPBGBUjDQ==","signature_status":"signed_v1","signed_at":"2026-05-18T00:43:54.011546Z","signed_message":"canonical_sha256_bytes"},"source_id":"1703.01019","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:39c03094e6cf36408d7c2289561193ead856c137110f3121971c1cfc3dfdbfa6","sha256:260736427d3062ecf3a11fba6c8324a7cb24af45f42fedc0f3419499dddc1444"],"state_sha256":"11375f23d541b305cf5dfaa020ad3f5da3ef755a881cbb2bd1bb7153bda8b9b6"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"tQFDZtdp5uxTE9pfGpLxQ6kBAtP/6CTiYFNl3UaMp2XdacxRsY61Qbs8b9RDDqOOoPFqD4+79gSc8hWUbZc+DA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-06T19:39:49.668545Z","bundle_sha256":"3fdc23f7ed3f420f70c4c7cde0e6a34f1fdda33c79cf794be2149bca75456d3c"}}