Self-consistent device simulation of germanium hole qubits

Germanium hole spin qubits have various advantages, including strong spin-orbit coupling that enables all-electrical control. Due to the strong spin-orbit coupling, the effective g-factor of a germanium hole quantum dot can be highly sensitive to applied gate voltages. To optimize qubit performance, it is desirable to understand this dependence in quantitative detail. In this theoretical study, we implement a multiband (heavy and light holes), k-dot-p theory simulation of a single-dot device, focusing on the qubit states. We include strain and self-consistent (Schrodinger-Poisson) device electrostatics. Our real-space implementation is broadly applicable to device simulation involving multiband physics.