Intrinsic staggered spin-orbit torque for the electrical control of antiferromagnets: Application to CrI3

Spin-orbit torque enables the electrical control of the orientation of ferromagnets' or antiferromagnets' order parameter. In this work we consider antiferromagnets in which the magnetic sublattices are connected by inversion+time-reversal symmetry, and in which the exchange and anisotropy energies are similar in magnitude. We identify the staggered dampinglike spin-orbit torque as the key mechanism for electrical excitation of the Neel vector for this case. To illustrate this scenario, we examine the two-dimensional van der Waals antiferromagnetic bilayer CrI3, in the n-doped regime. Using a combination of first-principles calculations of the spin-orbit torque and an analysis of the ensuing spin dynamics, we show that the deterministic electrical switching of the Neel vector is the result of dampinglike spin-orbit torque which is staggered on the magnetic sublattices.