Mechanism of N\'eel order switching in antiferromagnetic thin films revealed by magnetotransport and direct imaging.

We probe the current-induced switching of insulating antiferromagnet/heavy metals systems, by electrical spin Hall magnetoresistance measurements and direct imaging, finding that it occurs by domain wall (DW) motion. Our results reveal two switching mechanisms, based on the spin-current induced effective magnetic anisotropy variation and on the action of the spin torque on the DWs, that together lead to efficient switching. In particular, this allows us to explain how the threshold current density for the switching can be tuned, by varying the substrate and crystallographic NiO orientation.