The magnetic properties of hole quantum dots in Ge are sensitive to their shape due to the interplay between strong spin-orbit coupling and confinement. We show that the split-off band, surrounding SiGe layers, and hole-hole interactions have a strong influence on calculations of the effective g factor of a lithographic quantum dot in a Ge/SiGe heterostructure. Comparing predictions from a model including these effects to raw magnetospectroscopy data, we apply maximum-likelihood estimation to infer the shape of a quantum dot with up to four holes. We expect that methods like this will be useful in assessing qubit-to-qubit variability critical to further scaling quantum computing technologies based on spins in semiconductors.
@article{arxiv.2408.14422,
title = {Using a high-fidelity numerical model to infer the shape of a few-hole Ge quantum dot},
author = {Mitchell Brickson and N. Tobias Jacobson and Andrew J. Miller and Leon N. Maurer and Tzu-Ming Lu and Dwight R. Luhman and Andrew D. Baczewski},
journal= {arXiv preprint arXiv:2408.14422},
year = {2024}
}