Spin diffusion equation in superconductors in the vicinity of Tc
Spin diffusion equation in superconductors in the vicinity of Tc
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DOI：
10.1103/physrevb.98.214437
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发表时间：
2018-08
影响因子：
3.7
通讯作者：
Takuya Taira;M. Ichioka;S. Takei;H. Adachi
中科院分区：
文献类型：
--
作者：
Takuya Taira;M. Ichioka;S. Takei;H. Adachi
本文从微观上导出了超导转变温度Tc附近s波超导体中的自旋扩散方程。将弛豫函数和响应函数之间的一般关系应用于当前的自旋扩散问题，我们研究了自旋弛豫时间和自旋扩散系数在超导态下如何重整化。分析表明，低于Tc，自旋弛豫时间和自旋扩散系数都增加，导致自旋扩散长度的增加。这一结果可以解释最近在Py/Nb/Pt系统中观察到的Tc以下的增强的自旋泵浦信号，该系统没有相干峰效应。
We microscopically derive the spin diffusion equation in an s-wave superconductor in the vicinity of the superconducting transition temperature Tc. Applying the general relation between the relaxation function and the response function to the present spin diffusion problem, we examine how the spin relaxation time and the spin diffusion coefficient are renormalized in the superconducting state. The analysis reveals that, below Tc, both the spin relaxation time and the spin diffusion coefficient are increased, resulting in an enhancement of the spin diffusion length. The present result may provide an explanation for the recent observation of an enhanced spin pumping signal below Tc in a Py/Nb/Pt system that is free from the coherence peak effect.