Correction to: Nature https://doi.org/10.1038/s41586-020-2619-8 Published online 26 August 2020

In the ‘Radiation exposure experiment’ section of this Article, the average energy-relaxation rate of qubit Q2 should read \({\varGamma }_{1}^{({\rm{Q}}2)}=1/32\,{{\rm{\mu }}{\rm{s}}}^{-1}\) rather than  \({\omega }_{{\rm{q}}}^{({\rm{Q}}1)}=2{\rm{\pi }}\times 3.48\,{\rm{G}}{\rm{H}}{\rm{z}}\,{{\rm{\mu }}{\rm{s}}}^{-1}\). This error has been corrected online.