Efficient spin torques in antiferromagnetic CoO/Pt quantified by comparing field- and current-induced switching

Abstract

We achieve current-induced switching in collinear insulating antiferromagnetic CoO/Pt, with fourfold in-plane magnetic anisotropy. This is measured electrically by spin Hall magnetoresistance and confirmed by the magnetic field-induced spin-flop transition of the CoO layer. By applying current pulses and magnetic fields, we quantify the efficiency of the acting current-induced torques and estimate a currentfield equivalence ratio of 4 x 10(-11) T A(-1) m(2). The Neel vector final state (n perpendicular to j) is in line with a thermomagnetoelastic switching mechanism for a negative magnetoelastic constant of the CoO.