{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2026:5NXZHNLCCNVHONURVPDLVSHKAC","short_pith_number":"pith:5NXZHNLC","schema_version":"1.0","canonical_sha256":"eb6f93b562136a773691abc6bac8ea00851ae5be8a8689c59173add9d89c22fa","source":{"kind":"arxiv","id":"2607.01843","version":1},"attestation_state":"computed","paper":{"title":"Low-ancilla block encodings via Hamiltonian simulation","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Changpeng Shao, Yuxin Zhang","submitted_at":"2026-07-02T08:06:14Z","abstract_excerpt":"Block encodings are a central primitive in quantum algorithms, but standard constructions typically require logarithmic ancilla overhead and complicated controlled operations. Recent lower bounds further show that such ancilla overhead is unavoidable for exact constructions in broad circuit models. We show that this barrier can be bypassed in the approximate setting. Specifically, we present a simple single-ancilla construction that converts Hamiltonian evolution into a block encoding of the underlying Hamiltonian, via generalized quantum signal processing. For operators given by Hermitian dec"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"2607.01843","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2026-07-02T08:06:14Z","cross_cats_sorted":[],"title_canon_sha256":"61a98fc6ebc9701f45072f01e1e13cb6f1a1a734d003e4c883052c6f0617e5bf","abstract_canon_sha256":"32600dd73319ae2abd23fdb5259cfc2430089c6f9dcd6f12891015eb95e40b1d"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-03T01:17:31.403268Z","signature_b64":"EVi4neDZFYhpRI55CFzbzoDvXJL2S3ZeZU/tvJ+jtVErjB6frbmmfGXNjCcdjWzRPNlrhEOfhP9iq+Q5RZEwBQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"eb6f93b562136a773691abc6bac8ea00851ae5be8a8689c59173add9d89c22fa","last_reissued_at":"2026-07-03T01:17:31.402863Z","signature_status":"signed_v1","first_computed_at":"2026-07-03T01:17:31.402863Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Low-ancilla block encodings via Hamiltonian simulation","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Changpeng Shao, Yuxin Zhang","submitted_at":"2026-07-02T08:06:14Z","abstract_excerpt":"Block encodings are a central primitive in quantum algorithms, but standard constructions typically require logarithmic ancilla overhead and complicated controlled operations. Recent lower bounds further show that such ancilla overhead is unavoidable for exact constructions in broad circuit models. We show that this barrier can be bypassed in the approximate setting. Specifically, we present a simple single-ancilla construction that converts Hamiltonian evolution into a block encoding of the underlying Hamiltonian, via generalized quantum signal processing. For operators given by Hermitian dec"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.01843","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2607.01843/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"aliases":[{"alias_kind":"arxiv","alias_value":"2607.01843","created_at":"2026-07-03T01:17:31.402919+00:00"},{"alias_kind":"arxiv_version","alias_value":"2607.01843v1","created_at":"2026-07-03T01:17:31.402919+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2607.01843","created_at":"2026-07-03T01:17:31.402919+00:00"},{"alias_kind":"pith_short_12","alias_value":"5NXZHNLCCNVH","created_at":"2026-07-03T01:17:31.402919+00:00"},{"alias_kind":"pith_short_16","alias_value":"5NXZHNLCCNVHONUR","created_at":"2026-07-03T01:17:31.402919+00:00"},{"alias_kind":"pith_short_8","alias_value":"5NXZHNLC","created_at":"2026-07-03T01:17:31.402919+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/5NXZHNLCCNVHONURVPDLVSHKAC","json":"https://pith.science/pith/5NXZHNLCCNVHONURVPDLVSHKAC.json","graph_json":"https://pith.science/api/pith-number/5NXZHNLCCNVHONURVPDLVSHKAC/graph.json","events_json":"https://pith.science/api/pith-number/5NXZHNLCCNVHONURVPDLVSHKAC/events.json","paper":"https://pith.science/paper/5NXZHNLC"},"agent_actions":{"view_html":"https://pith.science/pith/5NXZHNLCCNVHONURVPDLVSHKAC","download_json":"https://pith.science/pith/5NXZHNLCCNVHONURVPDLVSHKAC.json","view_paper":"https://pith.science/paper/5NXZHNLC","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=2607.01843&json=true","fetch_graph":"https://pith.science/api/pith-number/5NXZHNLCCNVHONURVPDLVSHKAC/graph.json","fetch_events":"https://pith.science/api/pith-number/5NXZHNLCCNVHONURVPDLVSHKAC/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/5NXZHNLCCNVHONURVPDLVSHKAC/action/timestamp_anchor","attest_storage":"https://pith.science/pith/5NXZHNLCCNVHONURVPDLVSHKAC/action/storage_attestation","attest_author":"https://pith.science/pith/5NXZHNLCCNVHONURVPDLVSHKAC/action/author_attestation","sign_citation":"https://pith.science/pith/5NXZHNLCCNVHONURVPDLVSHKAC/action/citation_signature","submit_replication":"https://pith.science/pith/5NXZHNLCCNVHONURVPDLVSHKAC/action/replication_record"}},"created_at":"2026-07-03T01:17:31.402919+00:00","updated_at":"2026-07-03T01:17:31.402919+00:00"}