Spintronic Nano-Oscillators

Abstract

Spintronic nano-oscillators represent a novel class of nonlinear auto-oscillators that effectively convert magnetization precession into a microwave voltage signal by means of spin torque exerted through an electric current. These nano-oscillators can be categorized as either spin-torque nano-oscillators (STNOs) or spin-Hall nano-oscillators (SHNOs), depending on the driving force involved, namely, spin-transfer torque or spin-orbit torque. The present chapter offers a comprehensive review of the fundamental aspects and recent advancements in spintronic nano-oscillators. Firstly, the discussion encompasses spin torques and magnetoresistive effects. Subsequently, the underlying principles and theoretical foundations of spintronic nano-oscillators are elucidated, encompassing the Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation and nonlinear auto-oscillation theory. Additionally, the chapter outlines the structures, characteristics, and synchronization phenomena exhibited by these oscillators. Lastly, prospective applications such as microwave communication, assisted magnetic recording, and neuromorphic computing are explored. This review is poised to stimulate research interest, particularly with regard to the commercialization of promising applications.