Efficient Electrical Spin-Splitter Based on Non-Relativistic Collinear Antiferromagnetism

Electrical spin-current generation is among the core phenomena driving the field of spintronics. Using {\em ab initio} calculations we show that a room-temperature metallic collinear antiferromagnet RuO${}_2$ allows for highly efficient spin-current generation, arising from anisotropically-split bands with conserved up and down spins along the N'eel vector axis. The zero net moment antiferromagnet acts as an electrical spin-splitter with a 34${}^{\circ }$ propagation angle between spin-up and spin-down currents. Correspondingly, the spin-conductivity is a factor of three larger than the record value from a survey of 20,000 non-magnetic spin-Hall materials. We propose a versatile spin-splitter-torque concept utilizing antiferromagnetic RuO${}_2$ films interfaced with a ferromagnet.