{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2026:LJJHCQRVI2TG2E6DXJXBJOX4BI","short_pith_number":"pith:LJJHCQRV","canonical_record":{"source":{"id":"2606.30592","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2026-06-29T17:34:21Z","cross_cats_sorted":[],"title_canon_sha256":"74f9c4d26f2422cc93f573a303d512a1eeedf369333471f2177aafc30ae4e15c","abstract_canon_sha256":"a771709d1a15235fd70cd7205d5b5e586b03368a7884c02de524aecb4a3743d7"},"schema_version":"1.0"},"canonical_sha256":"5a5271423546a66d13c3ba6e14bafc0a1e0980777c1549eeb415ccad08486fe4","source":{"kind":"arxiv","id":"2606.30592","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.30592","created_at":"2026-06-30T02:18:21Z"},{"alias_kind":"arxiv_version","alias_value":"2606.30592v1","created_at":"2026-06-30T02:18:21Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.30592","created_at":"2026-06-30T02:18:21Z"},{"alias_kind":"pith_short_12","alias_value":"LJJHCQRVI2TG","created_at":"2026-06-30T02:18:21Z"},{"alias_kind":"pith_short_16","alias_value":"LJJHCQRVI2TG2E6D","created_at":"2026-06-30T02:18:21Z"},{"alias_kind":"pith_short_8","alias_value":"LJJHCQRV","created_at":"2026-06-30T02:18:21Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2026:LJJHCQRVI2TG2E6DXJXBJOX4BI","target":"record","payload":{"canonical_record":{"source":{"id":"2606.30592","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2026-06-29T17:34:21Z","cross_cats_sorted":[],"title_canon_sha256":"74f9c4d26f2422cc93f573a303d512a1eeedf369333471f2177aafc30ae4e15c","abstract_canon_sha256":"a771709d1a15235fd70cd7205d5b5e586b03368a7884c02de524aecb4a3743d7"},"schema_version":"1.0"},"canonical_sha256":"5a5271423546a66d13c3ba6e14bafc0a1e0980777c1549eeb415ccad08486fe4","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-06-30T02:18:21.931181Z","signature_b64":"crGbiXrWjITEs/oKajZGPFqMrntYvVcnsy32aB/yX1R3PtccxSp3OeUpwdf7ZvfcAsXrb1UTGxMIPYhcJGo0CA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"5a5271423546a66d13c3ba6e14bafc0a1e0980777c1549eeb415ccad08486fe4","last_reissued_at":"2026-06-30T02:18:21.930559Z","signature_status":"signed_v1","first_computed_at":"2026-06-30T02:18:21.930559Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2606.30592","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-06-30T02:18:21Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"s9D0mINzg7Jy+vzePeFNDkr97YKYLYlceSkURYYSEzYts3+GTFhoQZmLbqcgAdgkW4pg/AzPbaGPPlYfMa9pBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-01T00:13:44.140013Z"},"content_sha256":"1a2dad0521a491f89caf595c38a51e01c4e50d0b5052b71f90740399aea4a473","schema_version":"1.0","event_id":"sha256:1a2dad0521a491f89caf595c38a51e01c4e50d0b5052b71f90740399aea4a473"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2026:LJJHCQRVI2TG2E6DXJXBJOX4BI","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Untangling QLDPC Codes with Biased Noise Ancilla","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Kathleen Chang, Runjiang Bi, Shruti Puri","submitted_at":"2026-06-29T17:34:21Z","abstract_excerpt":"Remarkable technical progress has made high-rate, high-distance, quantum low-density parity-check codes (QLDPC) promising candidates for scalable quantum computing. However, it is hard to design low-depth syndrome extraction circuits that do not spread errors from ancilla qubits to multiple data qubits, also known as hook errors, for general QLDPC codes. Additionally, widely used decoders for these codes based on belief propagation are impaired due to short loops in the Tanner graph. Here, we investigate a hardware-aware approach to avoid these hooks and loops using biased noise ancillas. Usin"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.30592","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/2606.30592/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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-06-30T02:18:21Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"bjrlFKTtYf1Lz/MYwPkWW58eKgdN20HJBMOaz5AT1sYafoafAHyeL0ahq+CbwcTVr/84SxhwcU+i8DJ6sm8GCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-01T00:13:44.140746Z"},"content_sha256":"9386725c231e5336dc66e4f997b760c73b3ba02a46a2c68caa363a0aa27efb17","schema_version":"1.0","event_id":"sha256:9386725c231e5336dc66e4f997b760c73b3ba02a46a2c68caa363a0aa27efb17"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/LJJHCQRVI2TG2E6DXJXBJOX4BI/bundle.json","state_url":"https://pith.science/pith/LJJHCQRVI2TG2E6DXJXBJOX4BI/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/LJJHCQRVI2TG2E6DXJXBJOX4BI/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-07-01T00:13:44Z","links":{"resolver":"https://pith.science/pith/LJJHCQRVI2TG2E6DXJXBJOX4BI","bundle":"https://pith.science/pith/LJJHCQRVI2TG2E6DXJXBJOX4BI/bundle.json","state":"https://pith.science/pith/LJJHCQRVI2TG2E6DXJXBJOX4BI/state.json","well_known_bundle":"https://pith.science/.well-known/pith/LJJHCQRVI2TG2E6DXJXBJOX4BI/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:LJJHCQRVI2TG2E6DXJXBJOX4BI","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":"a771709d1a15235fd70cd7205d5b5e586b03368a7884c02de524aecb4a3743d7","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2026-06-29T17:34:21Z","title_canon_sha256":"74f9c4d26f2422cc93f573a303d512a1eeedf369333471f2177aafc30ae4e15c"},"schema_version":"1.0","source":{"id":"2606.30592","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.30592","created_at":"2026-06-30T02:18:21Z"},{"alias_kind":"arxiv_version","alias_value":"2606.30592v1","created_at":"2026-06-30T02:18:21Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.30592","created_at":"2026-06-30T02:18:21Z"},{"alias_kind":"pith_short_12","alias_value":"LJJHCQRVI2TG","created_at":"2026-06-30T02:18:21Z"},{"alias_kind":"pith_short_16","alias_value":"LJJHCQRVI2TG2E6D","created_at":"2026-06-30T02:18:21Z"},{"alias_kind":"pith_short_8","alias_value":"LJJHCQRV","created_at":"2026-06-30T02:18:21Z"}],"graph_snapshots":[{"event_id":"sha256:9386725c231e5336dc66e4f997b760c73b3ba02a46a2c68caa363a0aa27efb17","target":"graph","created_at":"2026-06-30T02:18:21Z","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/2606.30592/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Remarkable technical progress has made high-rate, high-distance, quantum low-density parity-check codes (QLDPC) promising candidates for scalable quantum computing. However, it is hard to design low-depth syndrome extraction circuits that do not spread errors from ancilla qubits to multiple data qubits, also known as hook errors, for general QLDPC codes. Additionally, widely used decoders for these codes based on belief propagation are impaired due to short loops in the Tanner graph. Here, we investigate a hardware-aware approach to avoid these hooks and loops using biased noise ancillas. Usin","authors_text":"Kathleen Chang, Runjiang Bi, Shruti Puri","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2026-06-29T17:34:21Z","title":"Untangling QLDPC Codes with Biased Noise Ancilla"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.30592","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":"sha256:1a2dad0521a491f89caf595c38a51e01c4e50d0b5052b71f90740399aea4a473","target":"record","created_at":"2026-06-30T02:18:21Z","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":"a771709d1a15235fd70cd7205d5b5e586b03368a7884c02de524aecb4a3743d7","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2026-06-29T17:34:21Z","title_canon_sha256":"74f9c4d26f2422cc93f573a303d512a1eeedf369333471f2177aafc30ae4e15c"},"schema_version":"1.0","source":{"id":"2606.30592","kind":"arxiv","version":1}},"canonical_sha256":"5a5271423546a66d13c3ba6e14bafc0a1e0980777c1549eeb415ccad08486fe4","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"5a5271423546a66d13c3ba6e14bafc0a1e0980777c1549eeb415ccad08486fe4","first_computed_at":"2026-06-30T02:18:21.930559Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-06-30T02:18:21.930559Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"crGbiXrWjITEs/oKajZGPFqMrntYvVcnsy32aB/yX1R3PtccxSp3OeUpwdf7ZvfcAsXrb1UTGxMIPYhcJGo0CA==","signature_status":"signed_v1","signed_at":"2026-06-30T02:18:21.931181Z","signed_message":"canonical_sha256_bytes"},"source_id":"2606.30592","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:1a2dad0521a491f89caf595c38a51e01c4e50d0b5052b71f90740399aea4a473","sha256:9386725c231e5336dc66e4f997b760c73b3ba02a46a2c68caa363a0aa27efb17"],"state_sha256":"2ed4a2de2c6033bfbe984bf05179f88107771bada7cdb096b9bbcc329a922bc9"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"olT4TEaSKmOp8Vwzrx76XrTNSPxijlo95ndWCFu1b9/dMfKEWZ4PHaoMV1SG3zNXuEMxvJM7dUo+gShD/EtSCQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-01T00:13:44.144097Z","bundle_sha256":"a79a3e3e72530a0b54c0e95d459781e4fb9951893e618d769fb4662bfa71dde3"}}