Device-level modeling of hole quantum dot qubits in germanium

Holes in Ge quantum wells in Ge/SiGe heterostructures have a number of promising properties that have made them the target of growing interest for qubit applications. These include strong intrinsic spin-orbit coupling, the absence of valley degeneracy, and small effective masses. In this talk, we will describe ongoing work towards developing comprehensive models of these systems to facilitate the design and optimization of devices and the rationalization of experiments. We make use of electrostatic/strain modeling to compute the potential landscape and capacitances of a given device structure. The potential landscape is fed into a multi-band effective mass theory, with other parameters drawn from first principles models, to extract a qubit Hamiltonian. We will report on work describing ongoing quantum dot experiments and make projections pertaining to qubit tunability and performance.