Strong variation of spin-orbit torques with relative spin relaxation rates in ferrimagnets

Abstract

There has been a lot of interest in using antiferromagnets for magnetic memories, due to their fast dynamics, and resilience to stray fields. Such a memory was supposed to be switched by a spin-orbit torque. Here, Zhu and Ralph find that as a ferrimagnet approaches the magnetic compensation point, the spin-orbit torque acting on the ferrimagnet vanishes due to competing spin relaxation processes.