Spin-torque switching of noncollinear antiferromagnetic antiperovskites

Abstract

Antiferromagnetic (AFM) spintronics exploits the N\'eel vector as a state variable for novel electronic devices. Recent studies have demonstrated that the N\'eel vector can be switched by a spin-orbit torque. These studies however are largely limited to collinear antiferromagnets of proper magnetic space-group symmetry. There is, however, a large group of high-temperature noncollinear antiferromagnets, which are suitable for such switching. Here, we predict that spin torque can be efficiently used to switch a noncollinear AFM order in antiperovskite materials. Based on first-principles calculations and atomistic spin-dynamics modeling, we show that in antiperovskites $A\mathrm{NM}{\mathrm{n}}_{3}$ ($A=\mathrm{Ga}$, Ni, etc.) with the AFM ${\mathrm{\ensuremath{\Gamma}}}_{4\mathrm{g}}$ ground state, the AFM order can be switched on the picosecond timescale using a spin torque generated by a spin current. The threshold switching current density can be tuned by the $A\mathrm{NM}{\mathrm{n}}_{3}$ stoichiometry engineering, changing the magnetocrystalline anisotropy. The ${\mathrm{\ensuremath{\Gamma}}}_{4\mathrm{g}}$ AFM phase supports a sizable anomalous Hall effect, which can be used to detect the spin-torque switching of the AFM order. The predicted ultrafast switching dynamics and the efficient detection of the AFM order state make noncollinear magnetic antiperovskites a promising material platform for AFM spintronics.