Error-Corrected Memory and Logic on a Heavy-Hex Superconducting-Qubit Processor
Abstract
Large quantum computations require high-fidelity error-corrected memory and fault-tolerant logical operations. To achieve these with superconducting circuits, quantum processors will need many components operating with low error rates. In practice, fabrication of monolithic superconducting devices produces unavoidable heterogeneity in component performance, which the quantum computer must accommodate. We implement strategies to operate a large dynamic compass code on an array of 156 superconducting qubits arranged on a heavy-hexagonal lattice, making use of the entire monolithic quantum processor and redesigning our measurement schedule to exclude underperforming components. We demonstrate improvements of up to 35% in logical error probabilities for a memory experiment by using a noise-informed decoder combined with strategies to exclude the worst-performing qubits and couplers, along with post-selecting on shots with a low probability of leakage errors. In addition to these memory results, we also observe performance gains of up to 56% when these strategies are applied to measurement-based logic, demonstrated by stability experiments. We furthermore demonstrate high-fidelity fault-tolerant logic through lattice surgery. Through pre-selection filtering techniques, we can obtain Bell fidelities above 77%, and further logical gap post-selection using exclusive decoding increases these fidelities to above 97%. Our experiments demonstrate that high performance can be maintained in key elements of fault-tolerant quantum memory and logic when working on monolithic superconducting quantum processors with underperforming components, by using a suite of noise-informed quantum error correction strategies.
Related
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BibTeX
@misc{mclauchlan2026errorcorrected,
title = {{Error-Corrected Memory and Logic on a Heavy-Hex Superconducting-Qubit Processor}},
author = {Campbell K. McLauchlan and Georgia M. Nixon and Julien M. Drouet and Xanda C. Kolesnikow and Seok-Hyung Lee and James Raftery and Karthik Siva and Stephen D. Bartlett and Benjamin J. Brown and Robin Harper},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.11658},
eprint = {2610.11658},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.11658},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Error-Corrected Memory and Logic on a Heavy-Hex Superconducting-Qubit Processor
AU - Campbell K. McLauchlan
AU - Georgia M. Nixon
AU - Julien M. Drouet
AU - Xanda C. Kolesnikow
AU - Seok-Hyung Lee
AU - James Raftery
AU - Karthik Siva
AU - Stephen D. Bartlett
AU - Benjamin J. Brown
AU - Robin Harper
PY - 2026
DA - 2026/10/08
PB - arXiv
DO - 10.48550/arxiv.2610.11658
UR - https://arxiv.org/abs/2610.11658
AB - Large quantum computations require high-fidelity error-corrected memory and fault-tolerant logical operations. To achieve these with superconducting circuits, quantum processors will need many components operating with low error rates. In practice, fabrication of monolithic superconducting devices produces unavoidable heterogeneity in component performance, which the quantum computer must accommodate. We implement strategies to operate a large dynamic compass code on an array of 156 superconducting qubits arranged on a heavy-hexagonal lattice, making use of the entire monolithic quantum processor and redesigning our measurement schedule to exclude underperforming components. We demonstrate improvements of up to 35% in logical error probabilities for a memory experiment by using a noise-informed decoder combined with strategies to exclude the worst-performing qubits and couplers, along with post-selecting on shots with a low probability of leakage errors. In addition to these memory results, we also observe performance gains of up to 56% when these strategies are applied to measurement-based logic, demonstrated by stability experiments. We furthermore demonstrate high-fidelity fault-tolerant logic through lattice surgery. Through pre-selection filtering techniques, we can obtain Bell fidelities above 77%, and further logical gap post-selection using exclusive decoding increases these fidelities to above 97%. Our experiments demonstrate that high performance can be maintained in key elements of fault-tolerant quantum memory and logic when working on monolithic superconducting quantum processors with underperforming components, by using a suite of noise-informed quantum error correction strategies.
ER -