Spin-flip hot spots in ultrathin films of monovalent metals: Enhancement and anisotropy of the Elliott-Yafet parameter
Spin-flip hot spots in ultrathin films of monovalent metals: Enhancement and anisotropy of the Elliott-Yafet parameter
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单价金属超薄膜中的自旋翻转热点：Elliott-Yafet 参数的增强和各向异性
DOI：
10.1103/physrevb.88.144408
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发表时间：
2013
影响因子：
3.7
通讯作者：
S. Blügel
中科院分区：
文献类型：
--
作者：
N. H. Long;P. Mavropoulos;S. Heers;B. Zimmermann;Y. Mokrousov;S. Blügel
与自旋翻转热点(即费米表面上显示高自旋混合参数的特定点)不同的是，我们在这些金属的超薄膜的表面布里渊区边界上发现了它们。用Korringa-Kohn-Rostoker格林函数方法对10层厚度的超薄Cu、Ag和Au薄膜进行的密度泛函计算表明，热点周围的区域对积分自旋混合参数有很大的贡献，例如Au(001)的52%，这可能导致薄膜的自旋弛豫速率或自旋霍尔角的显著提高。由于自旋翻转热点的出现，在这些系统中还发现了Elliott-Yafet参数的大的各向异性[Au(001)的50%]。这一发现对于频繁使用贵金属并降低样品维度的自旋电子学应用具有重要意义。
In contrast to the long-known fact that spin-flip hot spots, i.e., specialpoints on the Fermi surface showing a high spin-mixing parameter, do not occur in the bulk of monovalent (noble and alkali) metals, we found them on the surface Brillouin-zone boundary of ultrathin films of these metals. Density-functional calculations within the Korringa-Kohn-Rostoker Green function method for ultrathin (001) oriented Cu, Ag, and Au films of 10-layer thickness show that the region around the hot spots can have a substantial contribution, e.g., 52% in Au(001), to the integrated spin-mixing parameter, that could lead to a significant enhancement of the spin-relaxation rate or spin-Hall angle in thin films. Owing to the appearance of spin-flip hot spots, a large anisotropy of the Elliott-Yafet parameter [50% for Au(001)] is also found in these systems. The findings are important for spintronics applications in which noble metals are frequently used and in which the dimensionality of the sample is reduced.