{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:3PKT6LQBIDPFPK5T4JT5Q6T6IA","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":"09bdb4f18a3cefa07b73c051d9c8d7c0aa9ea25c4bc00c2ca267e9099a653f04","cross_cats_sorted":["cond-mat.mes-hall","physics.optics","quant-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2015-11-26T23:18:24Z","title_canon_sha256":"e866d5abfb9cd318c08e89226363044b7854d80218fc6bda81bfa8b69b6e7f9c"},"schema_version":"1.0","source":{"id":"1511.08527","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1511.08527","created_at":"2026-05-18T00:57:18Z"},{"alias_kind":"arxiv_version","alias_value":"1511.08527v1","created_at":"2026-05-18T00:57:18Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1511.08527","created_at":"2026-05-18T00:57:18Z"},{"alias_kind":"pith_short_12","alias_value":"3PKT6LQBIDPF","created_at":"2026-05-18T12:29:02Z"},{"alias_kind":"pith_short_16","alias_value":"3PKT6LQBIDPFPK5T","created_at":"2026-05-18T12:29:02Z"},{"alias_kind":"pith_short_8","alias_value":"3PKT6LQB","created_at":"2026-05-18T12:29:02Z"}],"graph_snapshots":[{"event_id":"sha256:7cde80f397e4599379e67ba3b5e4140dad4a866f9680319410493e75488e4b38","target":"graph","created_at":"2026-05-18T00:57:18Z","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 demonstrate experimentally that a cloud of cold atoms with a size comparable to the wavelength of light can induce large group delays on a laser pulse when the laser is tightly focused on it and is close to an atomic resonance. Delays as large as -10 ns are observed, corresponding to \"superluminal\" propagation with negative group velocities as low as -300 m/s. Strikingly, this large delay is associated with a moderate extinction owing to the very small size of the cloud and to the light-induced interactions between atoms. It implies that a large phase shift is imprinted on the continuous la","authors_text":"A. Browaeys, J.-J. Greffet, S. Jennewein, Y.R.P. Sortais","cross_cats":["cond-mat.mes-hall","physics.optics","quant-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2015-11-26T23:18:24Z","title":"Propagation of light through small clouds of cold interacting atoms"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1511.08527","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":"sha256:93efa773911dc0d52cbe6c16de0fa5d81d5a8c3cf317ae786aa99b8047010051","target":"record","created_at":"2026-05-18T00:57:18Z","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":"09bdb4f18a3cefa07b73c051d9c8d7c0aa9ea25c4bc00c2ca267e9099a653f04","cross_cats_sorted":["cond-mat.mes-hall","physics.optics","quant-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.atom-ph","submitted_at":"2015-11-26T23:18:24Z","title_canon_sha256":"e866d5abfb9cd318c08e89226363044b7854d80218fc6bda81bfa8b69b6e7f9c"},"schema_version":"1.0","source":{"id":"1511.08527","kind":"arxiv","version":1}},"canonical_sha256":"dbd53f2e0140de57abb3e267d87a7e40232ba34bab1534d56837ba7a90bc3ace","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"dbd53f2e0140de57abb3e267d87a7e40232ba34bab1534d56837ba7a90bc3ace","first_computed_at":"2026-05-18T00:57:18.063641Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:57:18.063641Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"ySgBcjObLbqWGK5wanrFrhxwZxH6m0sQm/Y/3lzMIGJoJQ/qJc6fLQms5O6FnT0xAH55PU94tT716wVMpAiaDA==","signature_status":"signed_v1","signed_at":"2026-05-18T00:57:18.064296Z","signed_message":"canonical_sha256_bytes"},"source_id":"1511.08527","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:93efa773911dc0d52cbe6c16de0fa5d81d5a8c3cf317ae786aa99b8047010051","sha256:7cde80f397e4599379e67ba3b5e4140dad4a866f9680319410493e75488e4b38"],"state_sha256":"c7321a19c8b732cdbbbbc180c0fa0d008d503569cf03e913030c210c6eed150a"}