Spin-Wave Emission by Spin-Orbit-Torque Antennas

Abstract

Energy-efficient excitation of spin waves is a fundamental building block---and also a major limiting factor---for a promising class of spintronic devices. Here researchers investigate spin-wave generation using a spin-orbit-torque (SOT) antenna, based on a heavy-metal/ferromagnet waveguide. Broadband excitation of propagating spin waves in a Ta/Co-Fe-B stack is demonstrated, while modeling and simulations reveal the details of the excitation, propagation, and mode formation. Finally, a simple circuit model shows the scaling properties of SOT antennas with respect to conventional inductive antennas. These results are a key step toward employing SOTs in spin-wave transducers.