{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:MSZM72EUIKG5GKQKKGCAQ4FDEF","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":"48078b46b3b8d2539e9ceb7cedf777e328214656e6cce47e4d533563c38fbfb1","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2015-03-09T15:15:35Z","title_canon_sha256":"8b0dc8ca5aa09b4d71e975fdf5e1d7997babe402c38f6caa94a49889658ccb0b"},"schema_version":"1.0","source":{"id":"1503.02514","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1503.02514","created_at":"2026-05-18T02:21:51Z"},{"alias_kind":"arxiv_version","alias_value":"1503.02514v1","created_at":"2026-05-18T02:21:51Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1503.02514","created_at":"2026-05-18T02:21:51Z"},{"alias_kind":"pith_short_12","alias_value":"MSZM72EUIKG5","created_at":"2026-05-18T12:29:32Z"},{"alias_kind":"pith_short_16","alias_value":"MSZM72EUIKG5GKQK","created_at":"2026-05-18T12:29:32Z"},{"alias_kind":"pith_short_8","alias_value":"MSZM72EU","created_at":"2026-05-18T12:29:32Z"}],"graph_snapshots":[{"event_id":"sha256:945721d68a26a26bd7e8044d220708c8237ee8308346e5c2778ed24bc1e157e0","target":"graph","created_at":"2026-05-18T02:21:51Z","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 improved circuits for the control-control-phase (Toffoli) gate and the control-swap (Fredkin) gate using three and four global two-qubit gates, respectively. This is a nearly double speed-up compared to the conventional circuits, which require five (for Toffoli) and seven (for Fredkin) conditional two-qubit gates. We apply the same approach to construct the conditional four-qubit phase gate by seven global two-qubit gates. We also present construction of the Toffoli and the Fredkin gates with five nearest-neighbour interactions. Our constructions do not employ ancilla qubits or anci","authors_text":"Nikolay V. Vitanov, Peter A. Ivanov, Svetoslav S. Ivanov","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2015-03-09T15:15:35Z","title":"Efficient construction of three- and four-qubit quantum gates by global entangling gates"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1503.02514","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:e5941e6bf064bd030ad0c4cc512ab081166f9f440bb4d40126efca65fc439aa5","target":"record","created_at":"2026-05-18T02:21:51Z","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":"48078b46b3b8d2539e9ceb7cedf777e328214656e6cce47e4d533563c38fbfb1","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2015-03-09T15:15:35Z","title_canon_sha256":"8b0dc8ca5aa09b4d71e975fdf5e1d7997babe402c38f6caa94a49889658ccb0b"},"schema_version":"1.0","source":{"id":"1503.02514","kind":"arxiv","version":1}},"canonical_sha256":"64b2cfe894428dd32a0a51840870a32143ef6b61c06facf793792f72b739df9a","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"64b2cfe894428dd32a0a51840870a32143ef6b61c06facf793792f72b739df9a","first_computed_at":"2026-05-18T02:21:51.210057Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:21:51.210057Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"7cl9Ej+oymfPklEwAZlJYuUft8kU7tJGtKo9c0RnO2ggnKdWVO6MnhhiIunQi9A+NdtkQ6iBTYsIFjER9CsABg==","signature_status":"signed_v1","signed_at":"2026-05-18T02:21:51.210784Z","signed_message":"canonical_sha256_bytes"},"source_id":"1503.02514","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e5941e6bf064bd030ad0c4cc512ab081166f9f440bb4d40126efca65fc439aa5","sha256:945721d68a26a26bd7e8044d220708c8237ee8308346e5c2778ed24bc1e157e0"],"state_sha256":"dc03671eb22aa25fbf28ceb7edc871d17aee9f8f0725bdc0ae5b990ad4b442f9"}