Extended Data Fig. 6: Heating effects.

a, A microwave burst of 16 GHz at 12 dBm output power and of a variable duration is applied before scanning the sensing dot virtual plunger gate. We observe no shift of the Coulomb peak, indicated by the white line, but the background signal increases substantially. Also the peak signal increases, but by a smaller amount. b, Linecut along the Coulomb peak and linecut parallel to the Coulomb peak of panel a, showing the peak and background signal as a function of the MW burst duration, for two different powers. The shaded area indicates the net signal, which is smaller the larger the applied power and the longer its duration. c, Variation on panel b, where we introduce a waiting time after the microwave burst, as indicated in the schematic. The longer the wait time, the more the original SNR is recovered, and the higher the readout fidelity will be. d, Rabi oscillations with different waiting times introduced before the qubit readout. The 500 μs wait time allows for recording long lived Rabi oscillations, while with no wait time prior readout, the contrast vanishes as the perceived spin fraction converge towards 1, due to shifts in the sensing dot signal and background (the threshold for single-shot analysis was kept fixed). e, Schematic showing the circuit used to investigate the effect of a pre-pulse (labelled MW burst (t)) on the qubit properties. A microwave burst of 6 dBm is applied before running a Ramsey experiment. We extract the change in T\({}_{2}^{* }\) and Larmor frequency for qubit Q5 for different microwave burst times as shown in the plots. f Return loss of the RF readout circuit for different powers of continued microwave driving (i.e. driving at the qubit frequencies, not for the RF readout). We observe both a shift in the RF resonance frequency and a degradation of the quality factor with higher power excitation. g, Extracted dephasing times T\({}_{2}^{* }\) with and without pre-pulse (4 μs, 6 dBm), measured as illustrated in e.