Probing spin-orbit induced leakage mechanisms via electric dipole spin-resonance within Pauli spin-blockade towards efficient hole spin qubit control

Silicon quantum dot (QD) devices show immense promise as spin qubits by offering longer coherence times as a result of a weak hyperfine interaction on a readily scalable platform that utilizes complementary metal-oxide-semiconductor (CMOS) compatible fabrication processes. The advantageous spin-orbit interaction strength of holes further promotes this architecture by enabling high-frequency electric dipole spin-resonance (EDSR), in contrast to electrons which require on-chip axillary structures to induce such a coupling. However, the fundamental nature of spin-orbit coupling within hole QD systems is still not yet fully understood.



In this work, we investigate the magnetic-field induced leakage current and g-factor dependence via EDSR of a hole double-QD MOS device within the weakly coupled (tunnel coupling ~ 1 µeV) Pauli-spin-blockade regime. Enhanced singlet-triplet state mixing as a result of spin-orbit coupling is observed to be highly directional with respect to an applied rotating field, yielding a variation in g-factors of more than 400% and a significant increase in leakage current based on orientation. As such, these results provide insight on the underlaying mechanisms which are crucial in understanding the role of spin-orbit coupling for hole spin qubit manipulation and readout.