Eline Raymenants

As the spin-qubit community closes in on error correction thresholds, precise device calibration and optimal operation have been reported to be affected by the so-called ‘heating effect’. As a workaround, our usual qubit sequences in Si/SiGe quantum dots have been composed by a pre-pulsing, off-resonant MW burst before any calibration or rotation is performed; and a cool-off idle time (~100us) before measurement. The pre-pulsing compensates for a frequency shift between the cold and the ‘heated’ states of the device, whereas the cool-off time allows visibility recovery in the sensors. After a few single-shots of the experiments, the devices reach a steady state. We study how the qubit frequency varies with temperatures, examine the possible mechanisms behind these phenomena and try to find an optimal temperature in which these effects are minimized.