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

A quantitative investigation of the current-induced torque in antiferromagnets represents a great challenge due to the lack of an independent method for controlling Neel vectors. By utilizing an antiferromagnetic insulator with the Dzyaloshinskii-Moriya interaction alpha-Fe2O3, we show that the Neel vector can be controlled with a moderate external field, which is further utilized to calibrate the current-induced magnetic dynamics. We find that the current-induced magnetoresistance change in antiferromagnets can be complicated by resistive switching that does not have a magnetic origin. By excluding nonmagnetic switching and comparing the current-induced dynamics with the field-induced one, we determine the nature and magnitude of current-induced effects in Pt/alpha-Fe2O3 bilayer films.