{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:FGA7GMBH3O5QSEEVW2LGTXK6RZ","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":"eb0b12a4198624ca21860032d2e0f41dbaadc0dfe1c8924b37ff3807d2e3ae97","cross_cats_sorted":["cond-mat.mes-hall"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2013-03-13T21:56:19Z","title_canon_sha256":"9b6c8c40e2c39eea34e1429096e67b7596d8e0e5a2299563603db36a210f9f7e"},"schema_version":"1.0","source":{"id":"1303.3300","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1303.3300","created_at":"2026-05-18T02:48:10Z"},{"alias_kind":"arxiv_version","alias_value":"1303.3300v2","created_at":"2026-05-18T02:48:10Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1303.3300","created_at":"2026-05-18T02:48:10Z"},{"alias_kind":"pith_short_12","alias_value":"FGA7GMBH3O5Q","created_at":"2026-05-18T12:27:45Z"},{"alias_kind":"pith_short_16","alias_value":"FGA7GMBH3O5QSEEV","created_at":"2026-05-18T12:27:45Z"},{"alias_kind":"pith_short_8","alias_value":"FGA7GMBH","created_at":"2026-05-18T12:27:45Z"}],"graph_snapshots":[{"event_id":"sha256:fbb4c26f79fe2930d2b9fe4c3c2ea76ddc20e84acde8878fa9a59fe2eec2e01e","target":"graph","created_at":"2026-05-18T02:48:10Z","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 reflectivity contrast provides a simple, fast and noninvasive method for characterization of few monolayer samples of two-dimensional materials. Here we apply this technique to measure the thickness of thin flakes of hexagonal Boron Nitride (hBN), which is a material of increasing interest in nanodevice fabrication. The optical contrast shows a strong negative peak at short wavelengths and zero contrast at a thickness dependent wavelength. The optical contrast varies linearly for 1-80 layers of hBN, which permits easy calibration of thickness. We demonstrate the applicability of this q","authors_text":"Arvinder Sandhu, Brian J. LeRoy, Dheeraj Golla, Kanokporn Chattrakun, Kenji Watanabe, Takashi Taniguchi","cross_cats":["cond-mat.mes-hall"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2013-03-13T21:56:19Z","title":"Optical thickness determination of hexagonal Boron Nitride flakes"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1303.3300","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":"sha256:6439b3583456652bf154bb01a26a9d0da0bdaae61820898627605e6b623589e0","target":"record","created_at":"2026-05-18T02:48:10Z","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":"eb0b12a4198624ca21860032d2e0f41dbaadc0dfe1c8924b37ff3807d2e3ae97","cross_cats_sorted":["cond-mat.mes-hall"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2013-03-13T21:56:19Z","title_canon_sha256":"9b6c8c40e2c39eea34e1429096e67b7596d8e0e5a2299563603db36a210f9f7e"},"schema_version":"1.0","source":{"id":"1303.3300","kind":"arxiv","version":2}},"canonical_sha256":"2981f33027dbbb091095b69669dd5e8e63a1eaa6c31804148b52f025fa6043fe","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"2981f33027dbbb091095b69669dd5e8e63a1eaa6c31804148b52f025fa6043fe","first_computed_at":"2026-05-18T02:48:10.060193Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:48:10.060193Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"kyxoU7KciTEXbHRs0WH3L0r6jS6yPE//l3B1N7CKBhrEE1+ttST04UA3Nl6QG1JoEbLSppgziRsr8pvyHWH0Bw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:48:10.060680Z","signed_message":"canonical_sha256_bytes"},"source_id":"1303.3300","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:6439b3583456652bf154bb01a26a9d0da0bdaae61820898627605e6b623589e0","sha256:fbb4c26f79fe2930d2b9fe4c3c2ea76ddc20e84acde8878fa9a59fe2eec2e01e"],"state_sha256":"392377feeafa825516488826c0a88d9136521c9a3c5cff8fe9bb2a009220ab46"}