Concepts of Spin Seebeck Effect in Ferromagnetic Metals
Concepts of Spin Seebeck Effect in Ferromagnetic Metals
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DOI：
10.1002/adfm.202004024
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发表时间：
2020-07
影响因子：
19
通讯作者：
Lizhi Yi;Dongchao Yang;Min Liu;H. Fu;L. Ding;Yunli Xu;Bingbing Zhang;L. Pan;J. Xiao
中科院分区：
文献类型：
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作者：
Lizhi Yi;Dongchao Yang;Min Liu;H. Fu;L. Ding;Yunli Xu;Bingbing Zhang;L. Pan;J. Xiao
自旋塞贝克效应（SSE）及其相关的自旋热电子学近年来引起了人们极大的兴趣。然而，SSE系数的定义仍有待建立，更不用说一个干净的实验来测量铁磁金属中的SSE系数。通过基于半经典Botlzmann输运方程的模型的概念已经得到澄清。该模型包括了重要的自旋翻转过程，这在金属中是常见的，并指出SSE的长度尺度远大于自旋扩散长度。该模型揭示了自旋翻转过程如何影响输运方程，并提供了自旋上和自旋下电子的不同自旋翻转弛豫时间之间的简单关系，这对于理解自旋输运性质非常有用。这种理解允许重新定义自旋塞贝克系数的表达式。
Spin Seebeck effect (SSE) and related spin caloritronics have attracted great interest recently. However, the definition of the SSE coefficient remains to be established, let alone a clean experiment to measure the SSE coefficient in ferromagnetic metals. The concept through a model based on the semi‐classical Botlzmann transport equation has been clarified. The model includes the vital spin‐flip process, which is frequent in metals, and points out that the length scale of SSE is much larger than the spin diffusion length. The model reveals how the spin‐flip process influences the transport equations and provides the simple relationship between the different spin‐flip relaxation times for spin‐up and ‐down electrons, which is very useful to understand the spin transport properties. This understanding allows to redefine the expression of the spin Seebeck coefficient.