{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:MLU4NJNUSWASBV6LTLNPFVWXX4","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":"5e10732480d9eebd96f2984401b9e9aac195eae3ba3360c578f312c4e0aee4f6","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2019-02-11T17:40:00Z","title_canon_sha256":"ff2908fc21ebc2b09d5cbe65854ed0e1e02242adf06c27c9059481eed7a1aac1"},"schema_version":"1.0","source":{"id":"1902.04012","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1902.04012","created_at":"2026-05-17T23:52:50Z"},{"alias_kind":"arxiv_version","alias_value":"1902.04012v1","created_at":"2026-05-17T23:52:50Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1902.04012","created_at":"2026-05-17T23:52:50Z"},{"alias_kind":"pith_short_12","alias_value":"MLU4NJNUSWAS","created_at":"2026-05-18T12:33:21Z"},{"alias_kind":"pith_short_16","alias_value":"MLU4NJNUSWASBV6L","created_at":"2026-05-18T12:33:21Z"},{"alias_kind":"pith_short_8","alias_value":"MLU4NJNU","created_at":"2026-05-18T12:33:21Z"}],"graph_snapshots":[{"event_id":"sha256:d6145736a35ed22b30786ecedbdc6d3a28bd0f3ee41ddb5a4eaecce975f14ef6","target":"graph","created_at":"2026-05-17T23:52:50Z","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 present a classical optics simulation of the one-dimensional Dirac equation for a free particle. Positive and negative energy components are represented by orthogonal polarizations of a free propagating beam, while the spatial profile represents the spatial wave function of the particle. Using a completely tunable time parameter, we observed the oscillation of the average value of the Dirac position operator - known as zitterbewegung (ZB). We are also able to measure the so called mean-position operator which is a single-particle observable and presents no oscillations. Our work opens the w","authors_text":"Ardiley T. Avelar, Emile R. F. Taillebois, Rafael. M. Gomes, Stephen P. Walborn, Thais de Lima Silva","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2019-02-11T17:40:00Z","title":"Optical simulation of the free Dirac equation"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1902.04012","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:c3f4b0c4f4ff6f5f283f8553980415841c8814be71c21ff02c2870546aa169f1","target":"record","created_at":"2026-05-17T23:52:50Z","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":"5e10732480d9eebd96f2984401b9e9aac195eae3ba3360c578f312c4e0aee4f6","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2019-02-11T17:40:00Z","title_canon_sha256":"ff2908fc21ebc2b09d5cbe65854ed0e1e02242adf06c27c9059481eed7a1aac1"},"schema_version":"1.0","source":{"id":"1902.04012","kind":"arxiv","version":1}},"canonical_sha256":"62e9c6a5b4958120d7cb9adaf2d6d7bf1dca814030506e27689496a78c69fb3e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"62e9c6a5b4958120d7cb9adaf2d6d7bf1dca814030506e27689496a78c69fb3e","first_computed_at":"2026-05-17T23:52:50.883963Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:52:50.883963Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"WeUJjRonUu6NnxgAp82wTBGe76GbOE/YPEPyPp8zA5VD9Z6EpKqFkgyUI2XkefPXTeQCLlNpYFMWrJsr6/DnDQ==","signature_status":"signed_v1","signed_at":"2026-05-17T23:52:50.884696Z","signed_message":"canonical_sha256_bytes"},"source_id":"1902.04012","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:c3f4b0c4f4ff6f5f283f8553980415841c8814be71c21ff02c2870546aa169f1","sha256:d6145736a35ed22b30786ecedbdc6d3a28bd0f3ee41ddb5a4eaecce975f14ef6"],"state_sha256":"1bc9ff977334e5abe95070500cee69b8b0ec292ce0fac2105a3440295e3a5dd5"}