Effective Out-of-plane G-Factor in Strained-Ge/sige Quantum Dots

Recently, lithographic quantum dots in strained-Ge/SiGe have become a promising candidate for quantum computation, with a remarkably quick progression from demonstration of a quantum dot to qubit logic demonstrations. Here we present a measurement of the out-of-plane g-factor for single-hole quantum dots in this material. As this is a single-hole measurement, this is the first experimental result that avoids the strong orbital effects present in the out-of-plane configuration. In addition to verifying the expected g-factor anisotropy between in-plane and out-of-plane magnetic (B)-fields, variations in the g-factor dependent on the occupation of the quantum dot are observed. These results are in good agreement with calculations of the g-factor using the heavy- and light-hole spaces of the Luttinger Hamiltonian, especially the first two holes, showing a strong spin-orbit coupling and suggesting dramatic g-factor tunability through both the B-field and the charge state.