Effects of Asymmetric Dzyaloshinskii-Moriya Interaction on Noncollinear Antiferromagnetic Spin Chiral Switching

Current-induced spin-orbit torque (SOT) switching is an efficient manipulation of noncollinear antiferromagnet states with exotic topological transport properties. However, stable switching of the spin chirality is still challenging, and the role of symmetry in SOT-driven switching is unclear. Here, we introduce asymmetric interfacial Dzyaloshinskii-Moriya interaction (DMI) by varying the value of one of the DMI vectors (D3). By using an atomistic model, it is shown that in Mn3Ir monolayer, stable spin chiral switching driven by SOT can be realized. In particular, it can effectively reduce the critical switching current density and the switching time by increasing the value of D3. We also provide switching phase diagrams with different D3 and SOT coefficients. Our results help further understand the switching mechanism of antiferromagnets and develop promising applications of antiferromagnetic (AFM) spintronic devices.