Martin-Rio Sergi, Frontera Carlos, Pomar Alberto, Balcells Lluis, Martinez Benjamin
Instituto de Ciencia de Materiales de Barcelona, ICMAB-CSIC, Campus UAB, 08193, Bellaterra, Spain.
Sci Rep. 2022 Jan 7;12(1):224. doi: 10.1038/s41598-021-04319-z.
Spin pumping (SP) is a well-established method to generate pure spin currents allowing efficient spin injection into metals and semiconductors avoiding the problem of impedance mismatch. However, to disentangle pure spin currents from parasitic effects due to spin rectification effects (SRE) is a difficult task that is seriously hampering further developments. Here we propose a simple method that allows suppressing SRE contribution to inverse spin Hall effect (ISHE) voltage signal avoiding long and tedious angle-dependent measurements. We show an experimental study in the well-known Py/Pt system by using a coplanar waveguide (CPW). Results obtained demonstrate that the sign and size of the measured transverse voltage signal depends on the width of the sample along the CPW active line. A progressive reduction of this width evidences that SRE contribution to the measured transverse voltage signal becomes negligibly small for sample width below 200 μm. A numerical solution of the Maxwell equations in the CPW-sample setup, by using the Landau-Lifshitz equation with the Gilbert damping term (LLG) as the constitutive equation of the media, and with the proper set of boundary conditions, confirms the obtained experimental results.
自旋泵浦（SP）是一种成熟的产生纯自旋电流的方法，可实现向金属和半导体的高效自旋注入，避免了阻抗失配问题。然而，将纯自旋电流与由于自旋整流效应（SRE）产生的寄生效应区分开来是一项艰巨的任务，严重阻碍了进一步的发展。在此，我们提出一种简单的方法，可抑制SRE对逆自旋霍尔效应（ISHE）电压信号的贡献，避免冗长乏味的角度相关测量。我们通过使用共面波导（CPW）在著名的Py/Pt系统中进行了一项实验研究。所获得的结果表明，测量到的横向电压信号的符号和大小取决于样品沿CPW有源线的宽度。该宽度的逐渐减小表明，对于宽度小于200μm的样品，SRE对测量到的横向电压信号的贡献变得可以忽略不计。通过使用包含吉尔伯特阻尼项（LLG）的朗道-里夫希茨方程作为介质的本构方程，并结合适当的边界条件集，对CPW-样品设置中的麦克斯韦方程组进行数值求解，证实了所获得的实验结果。
