A detailed understanding of the material properties that affect the splitting between the two low-lying valley states in Si/SiGe heterostructures will be increasingly important as the number of spin qubits is increased. Scanning gate microscopy has been proposed as a method to measure the spatial variation of the valley splitting as a tip-induced dot is moved around in the plane of the Si quantum well. We develop a simulation using an electrostatic model of the scanning gate microscope tip and the overlapping gate structure combined with an approximate solution to the three-dimensional Schr\"odinger-Poisson equation in the device stack. Using this simulation, we show that a tip-induced quantum dot formed near source and drain electrodes can be adiabatically moved to a region far from the gate electrodes. We argue that by spatially translating the tip-induced dot across a defect in the Si/SiGe interface, changes in valley splitting can be detected.
@article{arxiv.2405.03596,
title = {Towards Utilizing Scanning Gate Microscopy as a High-Resolution Probe of Valley Splitting in Si/SiGe Heterostructures},
author = {Efe Cakar and H. Ekmel Ercan and Gordian Fuchs and Artem O. Denisov and Christopher R. Anderson and Mark F. Gyure and Jason R. Petta},
journal= {arXiv preprint arXiv:2405.03596},
year = {2024}
}