Spin-orbit-torque-induced magnetization switching in <i>α</i> -W-based magnetic tunnel junction

Abstract Spin-orbit torque (SOT) provides an efficient and scalable way to induce magnetization dynamics and switch of nanomagnets using electrical currents. Many different material systems, such as heavy metals, topological insulators, and coupled multilayers, have been proposed and verified for efficient magnetization switching, with the main focus on a large spin Hall angle, which is typically accompanied by an increased resistivity of the spin-current source material. In this study, we present the spin Hall angle in α -W, characterized by low resistance and a moderate spin Hall angle. In-plane magnetized magnetic tunnel junctions have been fabricated on top of a W-channel, with the nanopillars characterized by an easy-axis oriented perpendicular to the current direction. SOT-induced magnetization switching was measured with the current density reaching 1 × 10 12 A m −2 without the presence of an external magnetic field. Contributions from both damping-like and field-like torques, as well as the Ørsted field associated with the current pulses, are discussed.