Spin-wave emission from spin-torque nano-oscillators and its control by microwave pumping

Abstract

Spin transfer torque is a unique mechanism enabling excitation of microwave-frequency oscillations in magnetic nanodevices by dc current, making them attractive for applications in microwave electronics as nanoscale microwave oscillators. Here we review our recent investigations of spin-wave emission by spin torque oscillators and show that these devices can be also used as emitters of high-frequency spin waves for the emerging field of magnonics, where spin waves are utilized as a medium for high-speed transmission and processing of electrical signals on the nanometer scale. We demonstrate that, due to the anisotropy of the spin-wave spectrum, the emission is strongly directional, and the direction of the spin-wave propagation is steerable by the magnetic field. Moreover, we show that the characteristics of the emitted spin waves can be controlled by using nonlinear dynamic magnetic processes. © Springer-Verlag Berlin Heidelberg 2013.