{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:7M2M7EYTYG5JTOSTI5BINVTPGZ","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":"9feaf0cca6b014338549f5b289db065c4a0455a3e81e44d22093cdbbbf94029e","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"quant-ph","submitted_at":"2026-07-08T21:38:39Z","title_canon_sha256":"c7f3dbed032bf65784103ed803fcd70be4ace0401b461087d429a3d1a3dd1a8a"},"schema_version":"1.0","source":{"id":"2607.07942","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2607.07942","created_at":"2026-07-10T00:19:05Z"},{"alias_kind":"arxiv_version","alias_value":"2607.07942v1","created_at":"2026-07-10T00:19:05Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2607.07942","created_at":"2026-07-10T00:19:05Z"},{"alias_kind":"pith_short_12","alias_value":"7M2M7EYTYG5J","created_at":"2026-07-10T00:19:05Z"},{"alias_kind":"pith_short_16","alias_value":"7M2M7EYTYG5JTOST","created_at":"2026-07-10T00:19:05Z"},{"alias_kind":"pith_short_8","alias_value":"7M2M7EYT","created_at":"2026-07-10T00:19:05Z"}],"graph_snapshots":[{"event_id":"sha256:455749c17dba5da3b66ec6334c044b289afea5ec6041e7d3c9194e99ee3607ce","target":"graph","created_at":"2026-07-10T00:19:05Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2607.07942/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Variational quantum algorithms depend on the geometry of their parametrised circuits: metric-aware optimisation and time evolution require the Fubini-Study metric, which has hitherto demanded costly auxiliary measurements and ill-conditioned inversions. This work introduces a hardware-efficient $n$-qubit ansatz, which parametrises states by a binary tree and whose Fubini-Study pullback metric is diagonal in closed form. Quantum natural gradient on the tree parameters, variational imaginary- and real-time evolution, and exact unitary-invariant (Haar) sampling on a symmetry sector run with no au","authors_text":"Dario Picozzi","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"quant-ph","submitted_at":"2026-07-08T21:38:39Z","title":"A hardware-efficient variational ansatz with an exact diagonal metric for real- and imaginary-time evolution and Haar sampling"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.07942","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":"sha256:3581dca50fe9d31fd1c8f10b3741e5c68e049edaae76c5d9ec06d71c3a3bb32d","target":"record","created_at":"2026-07-10T00:19:05Z","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":"9feaf0cca6b014338549f5b289db065c4a0455a3e81e44d22093cdbbbf94029e","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"quant-ph","submitted_at":"2026-07-08T21:38:39Z","title_canon_sha256":"c7f3dbed032bf65784103ed803fcd70be4ace0401b461087d429a3d1a3dd1a8a"},"schema_version":"1.0","source":{"id":"2607.07942","kind":"arxiv","version":1}},"canonical_sha256":"fb34cf9313c1ba99ba53474286d66f365f907e842a434ba4c94b752b03383a18","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"fb34cf9313c1ba99ba53474286d66f365f907e842a434ba4c94b752b03383a18","first_computed_at":"2026-07-10T00:19:05.464607Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-10T00:19:05.464607Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"oPG432SSFE88eoJWzHQcHWyRAa9hhF322jxwPtB4M2gtOnsDqeV0WID/r3yfODJBK0Ge2NhCr7E9RVWwvFeLCw==","signature_status":"signed_v1","signed_at":"2026-07-10T00:19:05.465762Z","signed_message":"canonical_sha256_bytes"},"source_id":"2607.07942","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:3581dca50fe9d31fd1c8f10b3741e5c68e049edaae76c5d9ec06d71c3a3bb32d","sha256:455749c17dba5da3b66ec6334c044b289afea5ec6041e7d3c9194e99ee3607ce"],"state_sha256":"26d5f399edefbcb108ba79c232db89a34d4b0c40ae09a793cc97be9ef7bfed8f"}