Fermi surfaces, spin-mixing parameter, and colossal anisotropy of spin relaxation in transition metals from ab initio theory
Abstract
The Fermi-surfaces and Elliott-Yafet spin-mixing parameter (EYP) of several elemental metals are studied by \emph{ab initio} calculations. We focus first on the anisotropy of the EYP as a function of the direction of the spin-quantization axis [Phys.~Rev.~Lett.\ \textbf{109}, 236603 (2012)]. We analyze in detail the origin of the gigantic anisotropy in hcp metals as compared to cubic metals by band-structure calculations and discuss the stability of our results against an applied magnetic field. We further present calculations of light (4 and 3) hcp crystals, where we find a huge increase of the EYP anisotropy, reaching colossal values as large as in hcp Ti. We attribute these findings to the reduced strength of spin-orbit coupling, which promotes the anisotropic spin-flip hot loops at the Fermi surface. In order to conduct these investigations, we developed an adapted tetrahedron-based method for the precise calculation of Fermi surfaces of complicated shape and accurate Fermi-surface integrals within the full-potential relativistic Korringa-Kohn-Rostoker Green-function method.
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Cite
@article{arxiv.1601.06605,
title = {Fermi surfaces, spin-mixing parameter, and colossal anisotropy of spin relaxation in transition metals from ab initio theory},
author = {Bernd Zimmermann and Phivos Mavropoulos and Nguyen H. Long and Christian-Roman Gerhorst and Stefan Blügel and Yuriy Mokrousov},
journal= {arXiv preprint arXiv:1601.06605},
year = {2016}
}