Predicted multiple Walker breakdowns for current-driven domain wall motion in antiferromagnets

Abstract

We theoretically discover the possible emergence of reentrant Walker breakdowns for current-driven domain walls in layered antiferromagnets, in striking contrast to the unique Walker breakdown in ferromagnets. We reveal that the Lorentz contraction of domain wall width in antiferromagnets gives rise to nonlinear current dependence of the wall velocity and the predicted multiple Walker breakdowns. The dominant efficiency of the current-induced staggered spin-orbit torque over the spin-transfer torque to drive the domain wall motion is also demonstrated. These findings are expected to be observed in synthetic antiferromagnets experimentally and provide an important contribution to the growing research field of antiferromagnetic spintronics.