Spin orbit torque in disordered antiferromagnets

Abstract

We investigate the current-induced spin-orbit torque in antiferromangnetic materials in the presence of Rashba spin orbit coupling using both the linear response theory and the non-equilibrium Green's function technique implemented on a tight-binding model. We show that a staggered spin density arises from interband contributions. The effect of the disorder is restricted to the diminution of the torque magnitude and does not bring any anomalous behavior to the dependences of the torque on the spin orbit strength and the exchange interaction between the antiferromagnetic local moments and the itinerant electrons spins. We prove that the spin orbit torque is robust against the application of the disorder compared to the case of the antiferromagnetic spin-valve spin transfer torque.