{"slug":"superconducting-qubits","topic":"superconducting-qubits","title":"Superconducting Quantum Processors: State of the Field (October 2026)","summary":"An expert briefing on superconducting quantum processors as of late October 2026: transmon, fluxonium and bosonic (GKP and cat) qubits; coherence, two-qubit gate and readout fidelity; surface-code memories and their error-suppression factor; beyond-classical experiments; and the wiring and control limits on scaling. The main takeaway is that a superconducting surface-code memory now outlives its best physical qubit, with an error-suppression factor of about 2.1 per distance step, while open problems include rare correlated errors and the control wiring that very large machines will need.","version":1,"published_at":"2026-10-30","updated_at":"2026-10-30","stats":{"words":3992,"citations":38,"claims":28,"timeline":20,"benchmarks":17,"open_problems":8,"key_papers":15,"glossary":17},"verification":{"status":"verified","method":"independent AI fact-check against cited sources (evidence pack + web checks); automated citation resolution","claims_checked":28,"issues_fixed":30,"verified_at":"2026-10-30"},"ai_assisted":true,"price":{"usd":"0.20","protocol":"x402","network":"eip155:84532","asset":"USDC"},"url":"https://space-kitty.com/dossiers/superconducting-qubits","preview_url":"https://space-kitty.com/api/v1/dossiers/superconducting-qubits/preview","purchase_url":"https://space-kitty.com/api/v1/dossiers/superconducting-qubits","toc":[{"level":2,"text":"Executive summary","anchor":"executive-summary"},{"level":2,"text":"Background and core concepts","anchor":"background-and-core-concepts"},{"level":2,"text":"Timeline of key milestones","anchor":"timeline-of-key-milestones"},{"level":2,"text":"State of the art","anchor":"state-of-the-art"},{"level":3,"text":"Transmons and coherence","anchor":"transmons-and-coherence"},{"level":3,"text":"Fluxonium","anchor":"fluxonium"},{"level":3,"text":"Two-qubit gates, crosstalk and ZZ suppression","anchor":"two-qubit-gates-crosstalk-and-zz-suppression"},{"level":3,"text":"Readout","anchor":"readout"},{"level":3,"text":"Error correction","anchor":"error-correction"},{"level":3,"text":"Beyond-classical and algorithmic demonstrations","anchor":"beyond-classical-and-algorithmic-demonstrations"},{"level":3,"text":"Quantitative benchmarks","anchor":"quantitative-benchmarks"},{"level":2,"text":"Open problems and active debates","anchor":"open-problems-and-active-debates"},{"level":2,"text":"Major programs and players","anchor":"major-programs-and-players"},{"level":2,"text":"Outlook: what to watch (next 12-18 months)","anchor":"outlook-what-to-watch-next-12-18-months"},{"level":2,"text":"Key papers","anchor":"key-papers"},{"level":2,"text":"Glossary","anchor":"glossary"}],"sample_claims":["Google's distance-7 surface-code memory on 101 qubits logged 0.143% +/- 0.003% logical error per 1.1 us cycle, with error suppression Lambda = 2.14 +/- 0.02 per distance step and a logical lifetime 2.4 +/- 0.3 times its best physical qubit.","In repetition codes run up to distance 29, logical performance is limited by rare correlated error events, about once per hour or once per 3 x 10^9 cycles."],"includes":["markdown","claims","timeline","benchmarks","open_problems","key_papers","glossary","bibliography"],"citation_count":38,"how_to_buy":"GET https://space-kitty.com/api/v1/dossiers/superconducting-qubits with an x402 client ($0.20, USDC on Base Sepolia (testnet))."}