{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:TMSATLK76YZQ6OBHEK3V2Z77MY","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":"32c9a5e6c9bf6ec0ffd255151f239fcac3e7e0ee745c4aeb98e6342f6cfcc819","cross_cats_sorted":["quant-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2019-04-25T09:02:02Z","title_canon_sha256":"73991acfdd382fcfbd16407ddc7d25ecd58312c996186f22406d3e1a6ff72bf9"},"schema_version":"1.0","source":{"id":"1904.11220","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1904.11220","created_at":"2026-05-17T23:47:45Z"},{"alias_kind":"arxiv_version","alias_value":"1904.11220v1","created_at":"2026-05-17T23:47:45Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1904.11220","created_at":"2026-05-17T23:47:45Z"},{"alias_kind":"pith_short_12","alias_value":"TMSATLK76YZQ","created_at":"2026-05-18T12:33:30Z"},{"alias_kind":"pith_short_16","alias_value":"TMSATLK76YZQ6OBH","created_at":"2026-05-18T12:33:30Z"},{"alias_kind":"pith_short_8","alias_value":"TMSATLK7","created_at":"2026-05-18T12:33:30Z"}],"graph_snapshots":[{"event_id":"sha256:e095d041ae36b5fa02bbfa9c99f2118a35e49de733c1ab32f142749798a41ce5","target":"graph","created_at":"2026-05-17T23:47:45Z","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":"Measurement of quantum systems inevitably involves disturbance in various forms. Within the limits imposed by quantum mechanics, however, one can design an \"ideal\" projective measurement that does not introduce a back action on the measured observable, known as a quantum nondemolition (QND) measurement. Here we demonstrate an all-electrical QND measurement of a single electron spin in a gate-defined quantum dot via an exchange-coupled ancilla qubit. The ancilla qubit, encoded in the singlet-triplet two-electron subspace, is entangled with the single spin and subsequently read out in a single s","authors_text":"Akito Noiri, Andreas D. Wieck, Arne Ludwig, Daniel Loss, Giles Allison, Jun Yoneda, Kenta Takeda, Kento Kawasaki, Matthieu R. Delbecq, Peter Stano, Seigo Tarucha, Shinichi Amaha, Takashi Nakajima, Tomohiro Otsuka","cross_cats":["quant-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2019-04-25T09:02:02Z","title":"Quantum nondemolition measurement of an electron spin qubit"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1904.11220","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:f601050a3b1dac2adee1a1098d5cb958057803024ac936265ff39ad13f8db624","target":"record","created_at":"2026-05-17T23:47:45Z","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":"32c9a5e6c9bf6ec0ffd255151f239fcac3e7e0ee745c4aeb98e6342f6cfcc819","cross_cats_sorted":["quant-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mes-hall","submitted_at":"2019-04-25T09:02:02Z","title_canon_sha256":"73991acfdd382fcfbd16407ddc7d25ecd58312c996186f22406d3e1a6ff72bf9"},"schema_version":"1.0","source":{"id":"1904.11220","kind":"arxiv","version":1}},"canonical_sha256":"9b2409ad5ff6330f382722b75d67ff66225bfc56b81447bcfdf1401ad02916dc","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"9b2409ad5ff6330f382722b75d67ff66225bfc56b81447bcfdf1401ad02916dc","first_computed_at":"2026-05-17T23:47:45.486014Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:47:45.486014Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"TeQ4Z1yNFZQ49kmVOjLhA6IMTIlMpBDW5RvXI8E9ld4jNMU96hvYLeEF/W58PRtl+iGF8KS6C+ODUlFt0UcRAA==","signature_status":"signed_v1","signed_at":"2026-05-17T23:47:45.486663Z","signed_message":"canonical_sha256_bytes"},"source_id":"1904.11220","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:f601050a3b1dac2adee1a1098d5cb958057803024ac936265ff39ad13f8db624","sha256:e095d041ae36b5fa02bbfa9c99f2118a35e49de733c1ab32f142749798a41ce5"],"state_sha256":"685b3270cb10bc3dcebc1409ccf0eacf383c642a42e366ddc7cddd74f8fabc51"}