Controlled nonlinear magnetic damping in spin-Hall nano-devices
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 route for the implementation of efficient active spintronic and magnonic devices driven by spin current. Nonlinear damping enhancement imposes strict limitations on the operation and efficiency of magnetic nano-devices. Here the authors show that nonlinear damping can be controlled by the ellipticity of magnetization precession, which provides a route for the implementation of efficient active spintronic and magnonic devices driven by spin current.