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arXiv · 2405.03596

Towards Utilizing Scanning Gate Microscopy as a High-Resolution Probe of Valley Splitting in Si/SiGe Heterostructures

Efe Cakar·H. Ekmel Ercan·Gordian Fuchs·Artem O. Denisov·Christopher R. Anderson·Mark F. Gyure·Jason R. Petta
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Abstract

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.

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Efe Cakar, H. Ekmel Ercan, Gordian Fuchs, Artem O. Denisov, Christopher R. Anderson, Mark F. Gyure, Jason R. Petta. 2024-05-06. Towards Utilizing Scanning Gate Microscopy as a High-Resolution Probe of Valley Splitting in Si/SiGe Heterostructures. https://doi.org/10.1063/5.0217704

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