Spin-Orbit-Torque Switching Mediated by an Antiferromagnetic Insulator

© 2019 American Physical Society. We report the observation of antiferromagnetic insulator-mediated spin-orbit-torque switching in Pt/NiO/Co1-xTbx heterostructures. By measuring the current-induced shift in the magnetic hysteresis loops and the second-harmonic anomalous Hall resistance, we quantitatively determine the spin-orbit-torque efficiency in Pt/NiO/Co1-xTbx samples with different NiO thicknesses, uncovering a systematic evolution of the magnetic switching behavior. The measured spin-orbit-torque efficiency is enhanced in the low NiO thickness regime (1-2 nm), highlighting the efficient spin manipulation across a disordered antiferromagnetic insulator.