Enhancement of Spin-Orbit Torque Generation from Antiferromagnetic Ordering in PdCrO₂

Efficient generation of current induced spin-orbit torque is one pathway to the development of energy efficient spintronic devices. One promising family of materials for this generation is non-colinear antiferromagnets, which are predicted to show large spin Hall conductivities and have the potential to generate unconventional torques. PdCrO₂ is a layered antiferromagnet with a frustrated, non-collinear spin structure. We measure the spin-orbit torque efficiency from thin film PdCrO₂ as a function of temperature and find that the efficiency decreases weakly with decreasing temperature until the Néel temperature (~34 K), where the efficiency increases sharply. We attribute this enhancement of spin-current generation to the antiferromagnetic ordering of PdCrO₂.