{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"c08d092760cb208324f92783df286625c8ac0ef49972a7174b9dd8f5cee5a281","created":"2026-10-03T07:18:09Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"3cc543e5cd732c77d8a8dea79fb62d411755ced5d367b3434b863f665cdb748e","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"qi.fault-tolerance-noise.exponential-suppression-scaling","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Recent chips showed that enlarging an error-correcting code cuts the error rate by a constant factor at each step. It is unknown whether this continues to the much larger codes that useful computations need, or whether rare correlated events set a floor.","posed_since":"","precise":"For surface-code memories on superconducting hardware, the logical error per cycle is modeled as $\\epsilon_L(d) \\sim A \\Lambda^{-(d+1)/2}$ with code distance $d$; Google Quantum AI (Nature 638, 920, 2025, arXiv:2408.13687) reported $\\Lambda$ of about 2.1 up to $d = 7$. Determine whether this law holds to $d \\ge 15 \\text{ and } \\epsilon_L \\le 10^{-10}$ per cycle, or whether correlated, leakage or drift events produce a floor; the answer is the measured $\\epsilon_L(d)$ curve or a validated model of its floor.","problem_ref":null,"references":"","settled_by":"Surface-code memory experiments at $d \\ge 15$ with logical error rates measured down to $10^{-10}$ per cycle, or an identified error mechanism that provably caps suppression.","status_note":"In the same 2025 work, repetition codes up to $d = 29$ reached a logical-error floor near $10^{-10}\\ \\text{per cycle}$ (approximate), set by rare correlated events occurring about once per hour.","title":"Does logical error suppression continue exponentially to large code distance","topic_ref":"80758bd22592650de3fabeac0b32e47b1837a24802ff82348134607b99eeaa5a"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"4b0b1c6e24820c4ae743cb2eb142f30d701b7bbbb0fff87f2bee05b72376ab2f","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"c2371c6208233a1209c563c177045de5470cfa57ced40720c1cd3369c77a3c09","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"dDsjVUpjHycqxZPWCA3kndJSBonztSZnLf6DObHiyEFxvqCu6VGtz995bjAJg4uiUJTpuvQ8D-h0MzROMHpICg"},"schema":"pubphys.envelope/1"},"record_hash":"4b0b1c6e24820c4ae743cb2eb142f30d701b7bbbb0fff87f2bee05b72376ab2f","leaf_index":1993}