Spin-torque control of the anomalous Hall effect in non-collinear antiferromagnets

Non-collinear antiferromagnets have recently aroused significant interest due to the non-vanishing Berry curvature and the associated anomalous Hall effect sensitive to the magnetic ordering. In this work, we explore series of antiperovskite compounds Ga_1-xNi_xNMn₃ with competing Γ_4g and Γ_5g phases, where the magnetic moments of Mn atoms are aligned in the (111) plane. An electric current flowing and polarized in the [111] direction produces a spin-transfer torque rotating the magnetic moments in the (111) plane. Based on the Landau-Lifshitz-Gilbert-Slonczewski equation, we explore spin dynamics in these non-collinear antiferromagnets and obtain conditions at which a pulse of the spin-polarized current can reverse the Néel vector and thus change the sign of the anomalous Hall conductivity. We find that the strength of the applied spin-polarized current density largely depends on the magnetocrystalline anisotropy energy controlling the stability of the Γ_4g and Γ_5g phases. Using density functional theory methods, we calculate the magnetocrystalline anisotropy energy in these antiperovskite compounds and find the optimum conditions for the current-induced reversal of the Néel vector.