Electric control of hole spin qubits in Ge quantum dot

Si- and Ge-based hole spin qubits have seen fruitful development both theoretically and experimentally in recent studies thanks to the intrinsically strong spin-orbit interaction (SOI) of holes. Multi-qubit array has already been achieved experimentally with minimal crosstalk and efficient qubit control [1]. However, the strong SOI of holes also makes the qubits sensitive to a multitude of environmental influences, as shown in our recent study on hole spin splitting in a Ge quantum dot [2]. Here we present our recent exploration of electric-dipole spin resonance (EDSR) in Ge hole spin qubits. This theoretical study is based on the effective-mass formalism combined with the LCAO technique in a finite-barrier model. We examine effects of system parameters as well as external control variables, such as heterostructure band alignment, quantum dot confinement, and applied electric and magnetic fields. The numerical results are also compared to an analytical treatment using perturbation theory.