Superconducting qubit decay and dephasing correlated with radiating events

A major issue currently impeding qubit error-correction is spatially correlated qubit decoherence which is likely caused by cosmic radiation. Superconducting microwave kinetic inductance detectors (MKIDs) are a promising candidate for detection of these events due to their sensitivity to phonon bursts in a substrate. We placed arrays of MKIDs above and below a qubit sample to observe correlations between radiation effects on these devices. Detected radiation events on an MKID chip triggered a series of qubit measurements pertaining to decay, decoherence, and state preparation. We observed a drop in expected qubit T1 and T2 times as well as significant state preparation error for measurements made immediately after a detected event. Further research in such a system will aid in formulating mitigation strategies against errors in large-scale qubit systems.

LLNL-ABS-870897