Fig. 2: Lifetime and decoherence measurements.
a Lifetime (T1) and coherence time with dynamical decoupling (T2,CPMG) of Device 18 over time. b Summary of T1 time series measurements of all devices fabricated with a wet etch and piranha cleaning steps. Details about the specific processing steps for each device are given in Supplementary Table 1 and “Methods.” The yellow line shows the median, while the box spans the middle two quartiles of the data. The whiskers show the extremal measurements. Data for Devices 13, 14, and 17 are the average of 19, 14, and 7 individual T1 measurements, respectively, while the rest are the average of at least 32 measurements. Each device was measured over a period of hours to days, and Devices 11 and 13 include data from multiple dilution refrigerator cycles. c T2,Echo measurement of Device 18, showing the excited state population Pe as a function of delay time Δt. Solid blue line shows a stretched exponential fit to the data. The fit gives T2,Echo = 249 ± 4 μs. d T2,CPMG of Device 11 as a function of the number of gates in a CPMG pulse sequence. The error bars denote one standard deviation in the data.
