Magnetization switching by manipulating the thickness of FM&HM layers

Magnetization switching with spin–orbit torque has attracted lots of attention due to its fast switching characteristics and low-power consumption. Increasing the conversion efficiency from charge current to spin current is one of hot topics in this area. We examine a method to find the optimum layer thickness of the ferromagnet and of the normal metal for efficient magnetization switching. By controlling the thickness of the ferromagnet and of the normal metal, we can change the sign and magnitude of the overall field-like torque, which enables faster switching. Our results suggest a method for fast switching in spin-orbit torque-induced cases, where the film thickness of the ferromagnet and the normal metal are controllable parameters to provide an efficient way of implementing spin-orbitronics devices.