Staggered spin-orbit torques in antiferromagnets*

Spin-orbit torques in a heterostructure composed of heavy metals and ferromagnets have been widely studied, with the aim of efficient electrical switching of the magnetization. Compared to ferromagnets, the order parameter of antiferromagnets (the Neel vector) is more robust to external magnetic fields, however, it is also more difficult to switch. Recent studies have demonstrated efficient control and switching of antiferromagnets with a fieldlike torque, due to a staggered electric-field induced spin density. In this work, we consider the electric field-induced staggered spin current and resulting staggered spin-orbit torque in a collinear antiferromagnet. We use orthorhombic CuMnAs as an example to compute the time-reversal-even and time-reversal-odd components of the electric field-induced torque and study the ensuing dynamics of the antiferromagnetic order parameter.