Observation of Giant Orbital Hall Effect in Si

Abstract: Controlling/storing information carriers, such as electron charge and spin, is key for modern information society, and significant efforts have been paid made to establish novel technologies at the nanoscale. The rise of Si-based semiconductor technology and magnetism-based technology has been motivated by the aforementioned demands. However, both technologies have been individually developed, with little effort in fusing them. Hence, establishing a technology to bridge semiconductor and magnetism-based technologies that would allow realization of a novel information device is strongly awaited. In line with this research strategy, the creation of a magnetic device using semiconductors would enable fundamental innovation. Here, we show that a mother material for modern electronics, Si, gives rise to a giant room-temperature orbital Hall effect (OHE), enabling the creation of novel energy-efficient magnetic memory via efficient torque generation. The orbital torque efficiency largely exceeds that of the archetypal metallic materials used in the OHE. Our achievement overtures the conventional understanding that nonmagnetic semiconductors cannot play a pivotal role in magnetic devices and paves a new avenue for creating novel information devices through the fusion of semiconductor and magnetism-based technologies.