Anisotropy of spin relaxation and transverse transport in metals
Anisotropy of spin relaxation and transverse transport in metals
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DOI：
10.1088/0953-8984/25/16/163201
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发表时间：
2012-06
期刊：
影响因子：
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通讯作者：
Y. Mokrousov;Hongbin Zhang;F. Freimuth;B. Zimmermann;N. H. Long;J. Weischenberg;Ivo Souza;P. Mavropoulo
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文献类型：
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作者：
Y. Mokrousov;Hongbin Zhang;F. Freimuth;B. Zimmermann;N. H. Long;J. Weischenberg;Ivo Souza;P. Mavropoulo
使用第一性原理方法，我们探索了块体金属中自旋弛豫和横向传输特性相对于顺磁体中自旋量子化轴或铁磁体中自发磁化的实空间方向的各向异性。由于自旋轨道耦合的存在，布洛赫态的轨道和自旋特征敏感地取决于自旋相对于晶轴的方向。这导致依赖于自旋轨道相互作用引起的带间混合的量的剧烈变化。对于在布里渊区表现出尖峰和不规则分布的量，例如自旋混合参数或电子态的贝里曲率，各向异性尤其引人注目。我们通过三种情况证明了这一点：（i）具有结构反演对称性的顺磁体中的 Elliott-Yafet 自旋弛豫机制； (ii) 铁磁体中固有的反常霍尔效应； (iii) 顺磁体中的自旋霍尔效应。我们讨论了这些特性对自旋极化传输应用所表现出的明显各向异性行为的影响。
Using first-principles methods we explore the anisotropy of the spin relaxation and transverse transport properties in bulk metals with respect to the real-space direction of the spin-quantization axis in paramagnets or of the spontaneous magnetization in ferromagnets. Owing to the presence of the spin–orbit coupling the orbital and spin character of the Bloch states depends sensitively on the orientation of the spins relative to the crystal axes. This leads to drastic changes in quantities which rely on interband mixing induced by the spin–orbit interaction. The anisotropy is particularly striking for quantities which exhibit spiky and irregular distributions in the Brillouin zone, such as the spin-mixing parameter or the Berry curvature of the electronic states. We demonstrate this for three cases: (i) the Elliott–Yafet spin-relaxation mechanism in paramagnets with structural inversion symmetry; (ii) the intrinsic anomalous Hall effect in ferromagnets; and (iii) the spin Hall effect in paramagnets. We discuss the consequences of the pronounced anisotropic behavior displayed by these properties for spin-polarized transport applications.