We present a ferromagnetic resonance (FMR) spin pumping experiment at room temperature in periodic arrays of permalloy nanodots of different radii deposited onto a 3D topological insulator Bi2Se3 film. We measure the dc voltage signal generated by spin-to-charge conversion of the pumped spin current due to the spin-orbit coupling in the bulk of Bi2Se3. In the nanostructured samples, two resonance peaks are observed, associated with Kittel and inhomogeneous edge modes, respectively. This more complex modal composition in comparison to continuous systems may provide additional advantages for development of prospective spintronic devices. We support our experimental results by theoretical calculations, which are based on micromagnetic modeling of the magnetization dynamics under FMR excitation in a nanodot. A numerical approach to the calculation of the spin-pumping voltage is proposed, and the efficiency of spin-to-charge conversion is estimated for two nanostructured samples with different dot sizes.

中文翻译：

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坡莫合金点拓扑绝缘体双层中的自旋泵浦和探测

我们在室温下在沉积在 3D 拓扑绝缘体 Bi2Se3 膜上的不同半径的坡莫合金纳米点的周期性阵列中提出了铁磁共振（FMR）自旋泵浦实验。我们测量了由于 Bi2Se3 本体中的自旋轨道耦合，泵浦自旋电流的自旋电荷转换产生的直流电压信号。在纳米结构样品中，观察到两个共振峰，分别与 Kittel 和非均匀边缘模式相关。与连续系统相比，这种更复杂的模态组合可以为前瞻性自旋电子器件的开发提供额外的优势。我们通过理论计算支持我们的实验结果，这些理论计算基于纳米点中 FMR 激发下磁化动力学的微磁建模。