Switching of Perpendicular Magnetization by Spin-Orbit Torque.

Magnetic materials with strong perpendicular magnetic anisotropy are of great interest for the development of nonvolatile magnetic memory and computing technologies due to their high stabilities at the nanoscale. However, electrical switching of such perpendicular magnetization in an energy-efficient, deterministic, scalable manner has remained a big challenge. This problem has recently attracted enormous efforts in the field of spintronics. Here, recent advances and challenges in the understanding of the electrical generation of spin currents, the switching mechanisms and the switching strategies of perpendicular magnetization, the switching current density by spin-orbit torque of transverse spins, the choice of perpendicular magnetic materials are reviewed, and the progress in prototype perpendicular SOT memory and logic devices toward the goal of energy-efficient, dense, fast perpendicular spin-orbit torque applications is summarized.