Automated long-range compensation of an rf quantum dot sensor

Understand

Charge sensing is a sensitive technique for probing quantum devices, of particular importance for spin qubit readout.

• To achieve good readout sensitivities, the proximity of the charge sensor to the device to be measured is a necessity.
• However, this proximity also means that the operation of the device affects, in turn, the sensor tuning and ultimately the readout sensitivity.
• We present an approach for compensating for this cross-talk effect allowing for the gate voltages of the measured device to be swept in a 1 V x 1 V window while maintaining a sensor configuration chosen by a Bayesian optimiser.