Antiferromagnet-based spintronics show unique advantages comparing to conventional spintronics. Their zero net magnetization and high excitation frequency avoid any mode-coupling with ferromagnets during ferromagnetic resonance. Furthermore, large anomalous Hall effect and spin Hall effect have been predicted for antiferro¬magnets. The physical origin of these effects, whether is from the heavy elements in the compounds or from the Berry phase of noncollinear spin textures requires experimental investigation. To address this problem, we studied the spin Hall effects in metallic antiferromagnet compounds, X50Mn50, where X = Fe, Pd, Ir, Pt (with increasing atomic number), using spin pumping and inverse spin Hall effect experiments. We measured the spin Hall angle of the antiferromagnets which follows the relationship PtMn > IrMn > PdMn > FeMn. This result highlights the important role of the spin orbit coupling of the heavy metals for the properties of the Mn based alloys through orbital hybridization. This was corroborated using first-principles calculations of the ordered alloys, which showed that the value of the spin Hall conductivity can vary significantly with crystal orientation and staggered magnetization. This work is a significant stepping-stone towards designing spintronics devices using antiferromagnets.
Spin Hall Effects in Metallic Antiferromagnets,
Wei Zhang, Matthias B. Jungfleisch, Wanjun Jiang, John E. Pearson, Axel Hoffmann, Frank Freimuth, and Yuriy Mokrousov,
Phys. Rev. Lett. 113, 196602 (2014)