Fig. 4: An industrial silicon spin qubit.
a, Rabi oscillations of the measured spin-up probability as a function of the microwave burst duration. b, CPMG experiment: the measured spin-up probability as a function of the free evolution time separating 50 π-pulses, with an artificial phase detuning on the last pulse. The data are fitted with A(cos(ωt + φ) + B)exp(−(t/T2CPMG)2) + C. The fitted CPMG coherence time T2CPMG is 3.7 ± 0.2 ms. c, Demodulated and normalized CPMG amplitude as a function of the total evolution time for different numbers n of π-pulses. d, Measured coherence time T2CPMG for different numbers of CPMG π-pulses. The orange line represents a fit through the data (excluding n = 1) following T2CPMG ∝ nexp(γ/(γ + 1)). We extract γ = 1.1 ± 0.2.
