Electrical Switching of Tristate Antiferromagnetic Neel Order in α-Fe2O3 Epitaxial Films

We demonstrate nondecaying, steplike electrical switching of tristate Neel order in Pt/alpha-Fe2O3 bilayers detected by the spin-Hall induced anomalous Hall effect. The as-grown Pt/alpha-Fe2O3 bilayers exhibit sawtooth switching behavior generated by current pulses. After annealing by a high pulse current, the Hall signals reveal single-pulse saturated, nondecaying, steplike switching. Together with control experiments, we show that the sawtooth switching is due to an artifact of Pt while the actual spin-orbit torque induced antiferromagnetic switching is steplike. Our Monte Carlo simulations explain the switching behavior of alpha-Fe(2)O(3 )Neel order among three in-plane easy axes.