Antidamping torque-induced switching in biaxial antiferromagnetic insulators

TL;DR

This paper demonstrates current-induced reversible switching of the Neel order in biaxial antiferromagnetic NiO/Pt heterostructures via antidamping torque, enabling all-electrical control in antiferromagnetic spintronics.

Contribution

It reveals a new mechanism for Neel order switching driven by antidamping torque in biaxial antiferromagnets, contrasting with field-like torque mechanisms in other materials.

Findings

Reversible resistance changes at room temperature with current thresholds around 10^7 A/cm^2.

Switching driven by antidamping torque aligns Neel order with current direction.

Method applicable to other biaxial antiferromagnets for electrical control.

Abstract

We investigate the current-induced switching of the Neel order in NiO(001)/Pt heterostructures,which is manifested electrically via the spin Hall magnetoresistance. Significant reversible changes in the longitudinal and transverse resistances are found at room temperature for a current threshold lying in the range of 10^7 A/cm^2. The order-parameter switching is ascribed to the antiferromagnetic dynamics triggered by the (current-induced) antidamping torque, which orients the Neel order towards the direction of the writing current. This is in stark contrast to the case of antiferromagnets such as Mn2Au and CuMnAs, where field-like torques induced by the Edelstein effect drive the Neel switching, therefore resulting in an orthogonal alignment between the Neel order and the writing current. Our findings can be readily generalized to other biaxial antiferromagnets, providing broad opportunities for all-electrical writing and readout in antiferromagnetic spintronics.