Role of spin-orbit coupling in the effective g-factor anisotropy of germanium hole-spin qubits confined to an asymmetric quantum dot potential

Hole-spin qubits in a germanium quantum dot have emerged as a promising platform for scalable semiconductor qubit devices. Among many advantages over their electron-spin counterpart, the hole-spin qubits possess a strong spin-orbit coupling, which allows all-electrical spin control without the need of auxiliary micromagnets for single-qubit gate operations. We present analytical as well as numerical results about the role of the spin-orbit coupling on the salient physical properties of hole spin qubits such as an effective g-factor in a more realistic quantum dot confinement. We find preferable directions for the applied in-plane electric and magnetic fields for conducting gate operations as well as for mitigating the spin qubit decoherence.