Ferromagnetic spin-vales and tunneling junctions are one of the most fundamental and important spintronics devices. Their functionality is based on two effects: the giant or tunneling magnetoresistance for electrical readout and the spin-transfer torque allowing for electrical switching. It has been predicted previously that the same functionality could be achieved with antiferromagnetic junctions, which would provide various advantages over ferromagnets, such as a much faster switching speed. However, these devices are very sensitive to disorder and have never been experimentally demonstrated .
Here we show that the key to obtaining robust spin-transfer torque and magnetoresistance in antiferromagnets is utilizing lower symmetry antiferromagnets, in which electrical current is spin-polarized . We consider junctions composed of non-collinear antiferromagnets and find a spin-transfer torque and magnetoresistance with a magnitude and robustness against disorder comparable to ferromagnetic junctions . Furthermore, our calculations reveal novel aspects of the torque in non-collinear junctions. In particular, we find that apart from the conventional spin-transfer torque, a novel self-generated torque appears. This torque is similar to a spin-orbit torque but has a non-relativistic origin. We also find that a torque appears for any configuration of the junction, in contrast to ferromagnetic junctions where the torque vanishes in the parallel or antiparallel configurations.
 J. Železný et al., Nature Physic 14, 220–228 (2018).
 J. Železný et al., PRL 119, 187204 (2017).
 S. Ghosh et al., arXiv:2109.01399 (2021)