Spin Hall Effects in Antiferromagnets

Recent experiments demonstrate that antiferromagnets exhibit a spin Hall effect. Calculations also indicate that the intrinsic contribution is important in determining the magnitude of the spin Hall angle. However, we do not know how the mean free path, exchange interaction, and spin-orbit coupling govern these results and how these factors might influence our understanding of experiments. To address these questions, we consider a minimal model of an antiferromagnet. We numerically compute the spin Hall conductance as a function of impurity concentration, exchange energy, and spin-orbit coupling. We find that the spin Hall conductance is considerably larger in antiferromagnetic systems compared to normal metals. This opens yet another avenue of using antiferromagnets in spintronics devices.