Divinskiy Boris, Urazhdin Sergei, Demokritov Sergej O, Demidov Vladislav E
Institute for Applied Physics and Center for Nonlinear Science, University of Muenster, Corrensstrasse 2-4, 48149, Muenster, Germany.
Department of Physics, Emory University, Atlanta, GA, 30322, USA.
Nat Commun. 2019 Nov 18;10(1):5211. doi: 10.1038/s41467-019-13246-7.
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.
与低振幅线性 regime 相比，由于不可避免地出现非线性，大振幅磁化动力学要复杂得多。基本非线性现象之一是非线性阻尼增强，这对磁性纳米器件的运行和效率施加了严格限制。特别是，非线性阻尼会阻止由向空间扩展的磁性区域注入自旋电流驱动的相干磁化自振荡的激发。在此，我们提出并通过实验证明，非线性阻尼可以通过磁化进动的椭圆率来控制。通过平衡对各向异性的不同贡献，我们将椭圆率最小化，并实现了由向微观磁盘注入空间扩展的自旋电流驱动的相干磁化振荡。我们的结果为实现由自旋电流驱动的高效有源自旋电子器件和磁子器件提供了一条途径。
