Synchronous Detection of Cosmic Rays and Correlated Errors in Superconducting Qubit Arrays

• DOI: 10.48550/arxiv.2402.03208
• Publication Date: 2024-02-05
• Authors: P. M. Harrington; Mingyu Li; Max Hays; W. Van De Pontseele; D. Mayer; H. D. Pinckney; Felipe Contipelli; Michael Gingras; Bethany M. Niedzi...; Hannah Stickler; Jonilyn Yoder; Mollie E. Schwartz; Jeffrey A. Grover; Kyle Serniak; William D. Oliver; J. A. Formaggio

Quantum information processing at scale will require sufficiently stable and long-lived qubits, likely enabled by error-correction codes. Several recent superconducting-qubit experiments, however, reported observing intermittent spatiotemporally correlated errors that would be problematic for conventional codes, with ionizing radiation being a cause. Here, we directly measured the cosmic-ray contribution to qubit errors. We accomplished this synchronously monitoring detectors energy-relaxation dynamics of 10 transmon qubits distributed across 5x5x0.35 mm$^3$ silicon chip. Cosmic rays caused rate 1/(10 min), accounting 17$\pm$1% all such events. Our responded essentially cosmic their secondary particles incident on chip, consistent independently arrival flux. Moreover, observed landscape superconducting gap in proximity Josephson junctions dramatically impacts response rays. Given practical difficulties associated shielding rays, our results indicate importance hardening -- example, engineering realization robust quantum error correction.