{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:5775DFKJNJOKW23R6BHQI2ZUIX","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":"146cca04a07aa46276e324353c7e011d42b70a8216dd28ddeb569b8fb26ab282","cross_cats_sorted":["cond-mat.mes-hall","physics.optics"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2018-10-11T19:27:01Z","title_canon_sha256":"26275b1a1b0bfc659837e8fe14d533fcc1f171191d8a497bb2da647317ece194"},"schema_version":"1.0","source":{"id":"1810.05215","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1810.05215","created_at":"2026-05-18T00:03:31Z"},{"alias_kind":"arxiv_version","alias_value":"1810.05215v1","created_at":"2026-05-18T00:03:31Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1810.05215","created_at":"2026-05-18T00:03:31Z"},{"alias_kind":"pith_short_12","alias_value":"5775DFKJNJOK","created_at":"2026-05-18T12:32:08Z"},{"alias_kind":"pith_short_16","alias_value":"5775DFKJNJOKW23R","created_at":"2026-05-18T12:32:08Z"},{"alias_kind":"pith_short_8","alias_value":"5775DFKJ","created_at":"2026-05-18T12:32:08Z"}],"graph_snapshots":[{"event_id":"sha256:159895bca174727471fd72b429abac9a0521ba6b4779bae43af1365212c0846a","target":"graph","created_at":"2026-05-18T00:03:31Z","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 mechanically exfoliated nanosheets of franckeite by quantitative optical microscopy. The analysis of transmission mode and epi-illumination mode optical microscopy images provides a rapid method to estimate the thickness of the exfoliated flakes at first glance. A quantitative analysis of the optical contrast spectra by means of micro-reflectance allows one to determine the refractive index of franckeite in a broad range of the visible spectrum through a fit of the acquired spectra to a Fresnel law based model.","authors_text":"Andres Castellanos-Gomez, Carmen Munuera, David Maeso, David P\\'erez De Lara, Elena L\\'opez-Elvira, Foad Ghasemi, Gabino Rubio-Bollinger, Mar Garcia-Hernandez, Patricia Gant, Riccardo Frisenda","cross_cats":["cond-mat.mes-hall","physics.optics"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2018-10-11T19:27:01Z","title":"Optical contrast and refractive index of natural van der Waals heterostructure nanosheets of franckeite"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1810.05215","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":"sha256:33e2c6dfc6eeb1d9816f9493ccf75b33d1d0b7745cdc8ea7405972a29328adbe","target":"record","created_at":"2026-05-18T00:03:31Z","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":"146cca04a07aa46276e324353c7e011d42b70a8216dd28ddeb569b8fb26ab282","cross_cats_sorted":["cond-mat.mes-hall","physics.optics"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2018-10-11T19:27:01Z","title_canon_sha256":"26275b1a1b0bfc659837e8fe14d533fcc1f171191d8a497bb2da647317ece194"},"schema_version":"1.0","source":{"id":"1810.05215","kind":"arxiv","version":1}},"canonical_sha256":"efffd195496a5cab6b71f04f046b3445c5c677e8e5a00c3a7ada7a87aba2633d","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"efffd195496a5cab6b71f04f046b3445c5c677e8e5a00c3a7ada7a87aba2633d","first_computed_at":"2026-05-18T00:03:31.308392Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:03:31.308392Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"fkraNeLjPpQNRz+58pvw4Hf1gQlBePrGgl/0qm3F3qwUGZBxmREkqu80I5+Nsu8DaJgDCFbapxHk5rIsRQc5DQ==","signature_status":"signed_v1","signed_at":"2026-05-18T00:03:31.308857Z","signed_message":"canonical_sha256_bytes"},"source_id":"1810.05215","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:33e2c6dfc6eeb1d9816f9493ccf75b33d1d0b7745cdc8ea7405972a29328adbe","sha256:159895bca174727471fd72b429abac9a0521ba6b4779bae43af1365212c0846a"],"state_sha256":"d6fc0ab48cc5a4a7e93ac468e1a51327977ce846554fb489893b4303c3801464"}