Crystals were believed to hold magic power in ancient time, and in modern era, have revolutionized some of the most important technologies for society, for example, silicon-based information technology. Spintronics is a leading candidate for next-generation technologies, which relies on the generation, transmission, manipulation, and detection of spin currents. Ferromagnetic resonance (FMR) spin pumping is a powerful technique in generating and understanding pure spin currents. Building on the excellent-quality Y3Fe5O12 (YIG) films grown by a unique sputtering technique and the exceptionally large inverse spin Hall effect (ISHE) signals enabled by these films, we have characterized pure spin transport in several classes of materials, including: nonmagnetic and ferromagnetic metals, nonmagnetic insulators, and antiferromagnetic insulators. These results provide insights into the mechanisms of spin Hall physics and spin-orbit coupling, and reveal surprisingly robust spin conduction in antiferromagnetic insulators, which opens a wide range of new opportunities for spintronics.
