Reduction of the switching current in perpendicularly magnetized nanomagnets using an antiferromagnetic coupling structure

This paper reports a current-induced magnetization switching with a nanosecond-scale pulse current in a nanomagnet using a perpendicularly magnetized synthetic antiferromagnetic coupling (p-AFC) structure. The results indicate that the magnetization switching current in the p-AFC structure is less than that in the single-nanomagnet structure with perpendicular anisotropy when the differences in thickness and saturation magnetization between the upper and lower layers of the p-AFC structure are small and the Gilbert damping constant is also small. The results also show that the p-AFC structure can reduce the switching current when the pulse duration is short and its structure is effective for a high-speed switching. The results of this study shall be useful in the design of spin-transfer torque random access memory.