Fig. 3: QP bursts by muons and γ-rays.
From: Cosmic-ray-induced correlated errors in superconducting qubit array
a Smoothed MQSCPJ ratio PMQSCPJ(blue lines, left scale) in a time period of ~599 s. The horizontal dashed line indicates a threshold of 0.31 above which the MQSCPJ peaks correspond to QP bursts. Thin green and pink lines are the voltage signals of MDA and MDB (right scale). In all, 41 QP bursts and 127 muon events are detected, and 10 coincident events (marked by vertical dashed lines) are identified from the simultaneous appearance of MQSCPJ, MDA, and MDB signals as shown in b, c near tx ~ 464 s. d Smoothed MQSBF ratio PMQSBF measured over 22,400 s with a threshold of 0.21. In all, 75 QP bursts, 4751 muon events (not shown due to overcrowding), and 12 coincident events are detected. e, f Histograms of the time intervals between neighboring coincident events (light blue bars) and QP bursts (blue bars) for MQSCPJ and MQSBF experiments, respectively. Lines are the corresponding exponential fits. g, h Averaged dynamic processes starting from each coincident events for MQSCPJ and MQSBF ratios, respectively. The error bars represent the standard deviations of the PMQSCPJ and PMQSBF for the coincident events. Lines are the exponential fits yielding the recombination times of 36 ± 3 μs and 21 ± 2 μs. To better describe the rapid process, the length of the smoothing window used in g is 2 sampling points, while no smoothing window is used in h. Source data are provided as a Source Data file.
