Quantitative Study on Current-Induced Effects in an Antiferromagnet Insulator/Pt Bilayer Film

Quantitative investigation on the current-induced torque in antiferromagnets represents a great challenge, due to the lack of an independent method for controlling Néel vectors. Here by utilizing an antiferromagnetic insulator with Dzyaloshinskii-Moriya interaction, α-Fe2O3, we show that the Néel vector can be controlled with a moderate external field, which is further utilized to calibrate the current-induced magnetic dynamics. In a Pt/α-Fe2O3(0001) bilayer film, we see that the current-induced magnetoresistance change in antiferromagnets can be complicated by resistive switching that is non-magnetic. By excluding non-magnetic switching, we reveal two significant magnetic contributions, the magnetoelastic effect and the field-like spin-orbit torque, and quantify their magnitudes. Our approach in principle is applicable to many other easy plane antiferromagnets, and would be beneficial for future systematic studies of current-induced antiferromagnetic dynamics.