Electrical Control of Perpendicular Magnetic Anisotropy and Spin-Orbit Torque-Induced Magnetization Switching

Voltage-driven oxygen ion migration in ferromagnetic metal/oxide heterostructures offers a highly effective means to tailor emergent interfacial functionalities. In heterojunctions with a core structure of Pt/Co/CoO/TiO₂ (TaO_x), it is demonstrated that exchange coupling of magnetic moments across the Co/CoO interface provides an extra source to stabilize the perpendicular magnetic anisotropy (PMA). Moreover, the strength of this interfacial coupling can be reversibly controlled through voltage-driven oxygen ion migration at the Co/CoO interface, resulting in electrical-field-controllable PMA. In combination with the spin current generated from Pt, it is revealed that the spin-orbit torque (SOT) switching of the perpendicular magnetization of Co can be turned ON/OFF by electrical field. Tunable PMA and SOT switching makes heavy metal/ferromagnetic metal/antiferromagnetic oxide heterojunctions a promising candidate to future voltage-controlled, ultralow-power, and high-density spintronics devices.