Various quantities that are important for the successful operation of spin qubits display a spatial character that cannot be probed with transport measurements alone. To optimize qubit design and performance, it is of interest to map out e.g. sources of charge noise, nanoscale magnetic and electric fields, current flow, and the location of quantum dots. In this talk, I will describe our efforts on using extremely sensitive scanning SQUID magnetometers and scanning quantum dot charge sensors for this purpose. Specifically, we employed these sensors to measure with high resolution and sensitivity the stray fields of nanomagnets designed for control of electron spin qubits, as well as the current flow in quantum information devices.
University of Basel
Scanning probe microscopy for spin qubits