Crosstalk analysis in single hole-spin qubits within highly anisotropic g-tensors

Abstract: Spin qubits based on valence band hole states are highly promising for quantum information processing due to their strong spin-orbit coupling and ultrafast operation speed. As these systems scale up, achieving high-fidelity single-qubit operations becomes essential. However, mitigating crosstalk effects from neighboring qubits in larger arrays, particularly for anisotropic qubits with strong spin-orbit coupling, presents a significant challenge. We investigate the impact of crosstalk on qubit fidelities during single-qubit operations and derive an analytical equation that serves as a synchronization condition to eliminate crosstalk in anisotropic media. Our analysis proposes optimized driving field conditions that can robustly synchronize Rabi oscillations and minimize crosstalk, showing a strong dependence on qubit anisotropy and the orientation of the external magnetic field. Taking experimental data into our analysis, we identify a set of parameter values that enable nearly crosstalk-free single-qubit gates, thereby paving the way for scalable quantum computing architectures.