{"schemaVersion":"maha-epistemic/1.0","evidencePolicyVersion":"mps/0.1","recordId":"urn:maha:record:transmon-qubit","canonicalPath":"/knowledge/quantum-systems/concepts/transmon-qubit","contentHash":"sha256:340e6f2510c0b2e12853062d54acfbb4970d920b82d2f66cbe25fb1f4f4a3959","generatedAt":"2026-08-24T00:00:00.000Z","publicationDecision":{"recordId":"urn:maha:record:transmon-qubit","publicEligible":true,"evaluatedAgainst":"maha-epistemic/1.0","reasons":[]},"claims":[{"id":"urn:maha:claim:transmon-energy-ratio","statement":"In the transmon design analysed by Koch and colleagues, increasing the ratio of Josephson energy to charging energy suppresses charge dispersion exponentially while anharmonicity decreases only by a weak power law.","claimKind":"theoretical-model","evidenceMaturity":"single-study","sourceIds":["source-koch-transmon-2007"],"scope":"Circuit quantization and numerical analysis of the transmon regime described in the 2007 Physical Review A paper.","boundary":"The model does not by itself establish a fabrication yield, device lifetime, logical error rate, system-scale advantage, or commercially useful fault-tolerant computer.","uncertainty":{"kind":"qualitative","statement":"The relationship is model- and parameter-dependent; this Phase 1 record does not reproduce a numerical device-specific uncertainty interval."},"replication":{"independentReplicationCount":null,"assessment":"Independent experimental implementations are outside this bounded source record and are not counted here.","asOfDate":"2026-08-24"}}],"sources":[{"id":"source-koch-transmon-2007","title":"Charge-insensitive qubit design derived from the Cooper pair box","authors":["Jens Koch","Terri M. Yu","Jay Gambetta","A. A. Houck","D. I. Schuster","et al."],"publisher":"Physical Review A, American Physical Society","publishedAt":"2007-10-12","url":"https://journals.aps.org/pra/abstract/10.1103/PhysRevA.76.042319","identifiers":[{"scheme":"doi","value":"10.1103/PhysRevA.76.042319"}],"exactLocator":"Abstract; Sections II–IV; equations and numerical analysis defining the transmon regime.","rights":{"basis":"citation-with-paraphrase","quotationUsed":false,"note":"The Maha page provides original summary and boundary language and links to the publisher record; no article passage is reproduced."},"establishes":"The source introduces and analyses the transmon circuit regime, including the different scaling of charge dispersion and anharmonicity with the Josephson-to-charging-energy ratio.","boundary":"It is a design and modelling paper, not proof of later processor-scale fault tolerance, manufacturing economics, or strategic advantage."}],"reviewEvents":[{"reviewerId":"maha-editorial-system","reviewerRole":"Phase 1 source-fidelity and boundary review","reviewedAt":"2026-08-24T00:00:00.000Z","verdict":"approve","rationale":"Approved as a bounded demonstration of how a theoretical model and physical-readiness claims remain separate."}]}