Spin-Dependent Transport Phenomena at 5 d -Electron Oxide Interfaces

Spin-orbit interaction in solids can be utilized for controlling spin-dependent transport phenomena. To realize them, we focus on thin films and interfaces of iridium (Ir) oxides since electron conduction there is dominated by 5d electrons with strong spin-orbit interaction. The first example is the inverse spin Hall effect, which converts a spin current into an electric voltage. The performance of IrO2 as a spin-current detector is better than those of noble metals. The second is the topological Hall effect originating from magnetic skyrmions. The epitaxial bilayers consisting of SrRuO3 and SrIrO3 enable us to generate skyrmions through artificially broken inversion symmetry at the interfaces. These results can be a step toward future spintronics.