Parametric resonance of spin waves in ferromagnetic nanowires tuned by spin Hall torque
Parametric resonance of spin waves in ferromagnetic nanowires tuned by spin Hall torque
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DOI：
10.1103/physrevb.106.144410
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发表时间：
2021-12
影响因子：
3.7
通讯作者：
Liu Yang;A. Jara;Zheng Duan;Andrew Smith;B. Youngblood;R. Arias;I. Krivorotov
中科院分区：
文献类型：
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作者：
Liu Yang;A. Jara;Zheng Duan;Andrew Smith;B. Youngblood;R. Arias;I. Krivorotov
对Ni${80}$Fe${20}$/Pt双层纳米线中自旋波本征模的参量共振进行了实验和理论研究。利用电检测磁共振，我们测量的自旋波本征模在横向磁化纳米线的频谱和研究这些本征模的微波磁场的参数激发。我们还开发了一个分析理论的自旋波本征模和它们的参数激发的纳米线的几何形状，考虑到在纳米线边缘的磁稀释。我们测量调谐的参数共振阈值的反阻尼自旋霍尔扭矩从直流的边缘和散装本征模式，这使我们能够独立地评估频率，阻尼和椭圆率的模式。我们发现理论和实验之间的一致性很好的参数共振的体积本征模式，但出现显着的差异的边缘模式。数据显示，边缘模式的椭圆率明显低于预期，这可以归因于纳米线边缘处的磁性的强烈修改。我们的工作表明，自旋波本征模的参数共振是一个敏感的探针的磁性在薄膜纳米磁体的边缘。
We present a joint experimental and theoretical study of parametric resonance of spin wave eigenmodes in Ni$_{80}$Fe$_{20}$/Pt bilayer nanowires. Using electrically detected magnetic resonance, we measure the spectrum of spin wave eigenmodes in transversely magnetized nanowires and study parametric excitation of these eigenmodes by a microwave magnetic field. We also develop an analytical theory of spin wave eigenmodes and their parametric excitation in the nanowire geometry that takes into account magnetic dilution at the nanowire edges. We measure tuning of the parametric resonance threshold by antidamping spin Hall torque from a direct current for the edge and bulk eigenmodes, which allows us to independently evaluate frequency, damping and ellipticity of the modes. We find good agreement between theory and experiment for parametric resonance of the bulk eigenmodes but significant discrepancies arise for the edge modes. The data reveals that ellipticity of the edge modes is significantly lower than expected, which can be attributed to strong modification of magnetism at the nanowire edges. Our work demonstrates that parametric resonance of spin wave eigenmodes is a sensitive probe of magnetic properties at edges of thin-film nanomagnets.