{"paper":{"title":"Hybrid Predictive Quantum Feedback: Extending Qubit Lifetimes Beyond the Wiseman-Milburn Limit","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"A hybrid ancilla and predictor feedback scheme extends qubit lifetimes beyond the Wiseman-Milburn limit by a factor of three to four.","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Ali Abu-Nada, Aryan Iliat, Russell Ceballos","submitted_at":"2025-11-15T09:45:47Z","abstract_excerpt":"Amplitude damping fundamentally limits qubit lifetimes by irreversibly leaking energy and information into the environment. Standard Wiseman--Milburn feedback offers only modest improvement because it acts on a single measured quadrature and its corrective drive is degraded by loop delay. We introduce a compact hybrid upgrade with two components: (i) a coherently coupled \\emph{ancilla} qubit that receives the homodyne current and feeds back \\emph{quantum-coherently} on the system, recovering information from \\emph{both} field quadratures and intentionally engineered to decay much faster than t"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Using IBM-scale parameters (baseline T1 = 50 μs), numerical simulations surpass the W–M limit, achieving ∼3–4× longer T1 together with improved population retention and integrated energy.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The ancilla is intentionally engineered to decay much faster than the system while remaining coherently coupled without introducing new decoherence channels, and that the supervised predictor can deliver accurate real-time forecasts of the homodyne current under hardware latency.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Hybrid feedback with a coherently coupled fast ancilla and a homodyne-current predictor achieves 3-4 times longer qubit T1 than the Wiseman-Milburn limit in Lindblad-derived rates and IBM-scale simulations.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"A hybrid ancilla and predictor feedback scheme extends qubit lifetimes beyond the Wiseman-Milburn limit by a factor of three to four.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"ff706d565eed2b399da23ed5af615ec4508afa3dbab195c79a20c0a732e40eec"},"source":{"id":"2511.13774","kind":"arxiv","version":3},"verdict":{"id":"290eb22c-3d4d-432a-8f54-4f7477077c92","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-17T21:54:59.539240Z","strongest_claim":"Using IBM-scale parameters (baseline T1 = 50 μs), numerical simulations surpass the W–M limit, achieving ∼3–4× longer T1 together with improved population retention and integrated energy.","one_line_summary":"Hybrid feedback with a coherently coupled fast ancilla and a homodyne-current predictor achieves 3-4 times longer qubit T1 than the Wiseman-Milburn limit in Lindblad-derived rates and IBM-scale simulations.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The ancilla is intentionally engineered to decay much faster than the system while remaining coherently coupled without introducing new decoherence channels, and that the supervised predictor can deliver accurate real-time forecasts of the homodyne current under hardware latency.","pith_extraction_headline":"A hybrid ancilla and predictor feedback scheme extends qubit lifetimes beyond the Wiseman-Milburn limit by a factor of three to four."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2511.13774/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":36,"sample":[{"doi":"","year":2001,"title":"Non- markovian homodyne-mediated feedback on a two-level atom: a quantum trajectory treatment,","work_id":"3de8e964-4e78-4916-bfce-95b81a785c43","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2002,"title":"H.-P. Breuer and F. Petruccione,The Theory of Open Quantum Systems. Oxford University Press, 2002","work_id":"75fa39a8-af5b-4050-b5fc-607b45dee425","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2010,"title":"M. A. Nielsen and I. L. Chuang,Quantum computation and quantum information. Cambridge University Press, 2010","work_id":"5782617b-40c2-4981-98ba-37603b5ee6db","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2019,"title":"A quantum engineer’s guide to superconducting qubits,","work_id":"daafbc62-4532-47dc-94dc-7f3e95274693","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2024,"title":"Optimizing quantum gates towards the scale of logical qubits,","work_id":"b0ab3f5f-8014-47bb-9e05-5c630cbd566f","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":36,"snapshot_sha256":"3bb573233be356728cc23d7893195a00730e495fc489f1bf4ec656fae61c979a","internal_anchors":1},"formal_canon":{"evidence_count":2,"snapshot_sha256":"02b860ba138a68a672cf00bfc539e88df2cde64ec557e01632e461c5b70110f6"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}