Fig. 4: Predicted vs. measured transmon quality factors.
a Representative Al- and Ta-based transmon T1 curves showing an almost factor of 2 improvement by adopting a tantalum-based process. b Measured transmon Qint compared with predictions. Stars represent the 90th percentile transmon Qint of a distribution formed from repeated coherence measurements over a 10-h period. Shaded regions represent a predicted range spanning one standard deviation away from predicted transmon Qint. Measured qubit frequencies ranged from 4.5 to 6.7 GHz.
