Controlled nonlinear magnetic damping in spin-Hall nano-devices

TL;DR

This paper demonstrates a method to control nonlinear damping in spin-Hall nano-devices by adjusting magnetization precession ellipticity, enabling coherent oscillations and advancing spintronic device efficiency.

Contribution

It introduces a novel approach to reduce nonlinear damping through anisotropy balancing, facilitating coherent magnetization oscillations in extended magnetic regions.

Findings

Nonlinear damping can be controlled by precession ellipticity.

Minimizing ellipticity enables coherent oscillations in magnetic disks.

The method improves the efficiency of spintronic devices.

Abstract

Large-amplitude magnetization dynamics is substantially more complex compared to the low-amplitude linear regime, due to the inevitable emergence of nonlinearities. One of the fundamental nonlinear phenomena is the nonlinear damping enhancement, which imposes strict limitations on the operation and efficiency of magnetic nanodevices. In particular, nonlinear damping prevents excitation of coherent magnetization auto-oscillations driven by the injection of spin current into spatially extended magnetic regions. Here, we propose and experimentally demonstrate that nonlinear damping can be controlled by the ellipticity of magnetization precession. By balancing different contributions to anisotropy, we minimize the ellipticity and achieve coherent magnetization oscillations driven by spatially extended spin current injection into a microscopic magnetic disk. Our results provide a novel route for the implementation of efficient active spintronic and magnonic devices driven by spin current.