Selective Excitation of Localized Spin-Wave Modes by Optically Pumped Surface Acoustic Waves
Selective Excitation of Localized Spin-Wave Modes by Optically Pumped Surface Acoustic Waves
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DOI：
10.1103/physrevapplied.10.034068
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发表时间：
2018-09-28
影响因子：
4.6
通讯作者：
Hayward, T. J.
中科院分区：
文献类型：
--
作者：
Chang, C. L.;Tamming, R. R.;Hayward, T. J.
我们探索了用声表面波激发铁磁纳米结构中局域自旋波模的可行性。利用时间分辨的法拉第效应来探测镍纳米线阵列的磁化动力学。光抽运脉冲同时激发纳米线的自旋波模式和衬底的声学模式，我们观察到，当这些模式的频率一致时，由于两者之间的磁弹性耦合，磁化动力学的幅度大大增强。值得注意的是，通过调节外加磁场的大小，光激励表面声波可以选择性地激发纳米线自旋波谱中分裂的上或下分支，微磁模拟表明这是由纳米线不同部分的自旋波局部化引起的。因此，我们的结果表明，利用声波来选择性地激发空间受限的自旋波是可行的，这种方法可能会在未来的磁子装置中找到用处，在那里相干结构变形可以被用作传播自旋波的相干源。
We explore the feasibility of exciting localized spin-wave modes in ferromagnetic nanostructures using surface acoustic waves. The time-resolved Faraday effect is used to probe the magnetization dynamics of an array of nickel nanowires. The optical-pump pulse excites both spin-wave modes of the nanowires and acoustic modes of the substrate and we observe that, when the frequencies of these modes coincide, the amplitude of magnetization dynamics is substantially enhanced due to magnetoelastic coupling between the two. Notably, by tuning the magnitude of an externally applied magnetic field, optically excited surface acoustic waves can selectively excite either the upper or lower branches of a splitting in the nanowire's spin-wave spectrum, which micromagnetic simulations indicate is caused by localization of spin waves in different parts of the nanowire. Thus, our results indicate the feasibility of using acoustic waves to selectively excite spatially confined spin waves, an approach that may find utility in future magnonic devices where coherent structural deformations could be used as coherent sources of propagating spin waves.