Spin-Related Effects in Heavy Metal/Ferromagnet/Antiferromagnet Layer Structure

Spin-Orbit Torque in heavy metal/ferromagnetic (HM/FM) layer structure has recently attracted a lot of attention due to the possibility of magnetization switching [1], [2]. In three terminal spintronic devices the spin-orbit torque can deliver a fast and reliable operation which separates the writing and reading path [3]. In a HM/FM layer structure a current in the HM will produce the bulk spin Hall effect as well as the Rashba effect occurring at the HM/FM interface. Similar effects are expected in an antiferromagnetic (AFM) layer in contact with an FM layer. In this work, we report on the electrical tuning of the coercivity of the FM layer in a HM/FM/AFM heterostructure leading to a 70% decrease in coercivity as seen in Figure 1. This is attributed to a current induced modification of the AFM states and spin-orbit torque from the HM. As the bias current is increased, we observed that both the coercivity and exchange bias field decreases.