Control of spin-orbit torques through magnetic symmetry in differently oriented noncollinear antiferromagnetic Mn3Pt

Interconversion of charge and spin currents via spin Hall effect is one of the key physical phenomena in spintronics. However, the spin polarizations are orthogonal to both the charge and spin flows due to the restricted symmetry conditions. Here, we use noncollinear antiferromagnet Mn3Pt, which has different magnetic mirror planes in different orientations, to investigate magnetic symmetry dependent atypical spin-orbit torques. We observed weak generation of out of plane spin polarization (sigma(z)) in Mn3Pt/permalloy bilayers when current was applied perpendicular to the magnetic mirror plane of Mn3Pt, and strong generation of sz when current was applied parallel to the magnetic mirror plane. All three oriented Mn3Pt films show the same pattern, indicating the generation of unconventional sz has strong dependence on magnetic symmetry. Controlling spin-orbit torques by changing current directions in differently oriented Mn3Pt films provides a strategy for optimizing antiferromagnetic spintronics.