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@PHDTHESIS{Zimmermann:171881,
author = {Zimmermann, Bernd},
title = {$\textit{{A}b initio}$ description of transverse transport
due to impurity scattering in transition-metals},
volume = {89},
school = {RWTH Aachen},
type = {Dr.},
address = {Jülich},
publisher = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
reportid = {FZJ-2014-05437},
isbn = {978-3-89336-985-0},
series = {Schriften des Forschungszentrums Jülich. Reihe
Schlüsseltechnologien / Key Technologies},
pages = {164 S.},
year = {2014},
note = {RWTH Aachen, Diss., 2010},
abstract = {This thesis attempts to shed light on various spin-orbit
driven transport phenomenain materials, as a crucial for the
further development of the field of spintronics.
Inparticular, we address the skew-scattering mechanism in
dilute alloys, which gives rise to the anomalous and spin
Hall effect, as well as spin-relaxation processes. We create
the tools to access these quantities from $\textit{ab
initio}$ calculations in the framework of the full-potential
all-electron Korringa-Kohn-Rostoker Green-function method,
by (a) developing and implementing a new tetrahedron method
for the calculation of complicated, multi-sheeted Fermi
surfaces even of complex transition-metal compounds, and (b)
developing an efficiently parallelized and thus highly
scalable computer program (up to thousands of processors)
for the precise calculation of scattering properties. In a
first application of the new tetrahedron method, we
calculate the Elliott-Yafet spin-mixing parameter on the
Fermi surfaces of 5$\textit{d}$ and 6$\textit{sp}$ metals,
and discover a yet unexplored dependence on the electron's
spin-polarization direction. As we show, this anisotropy can
reach gigantic values in uniaxial hcp crystals due to the
emergenceof large spin-ip hot-areas or hot-loops on the
Fermi surface, supported by the low symmetry of the hcp
crystal. A simple model is able to reveal an interesting
interplay between the orbital character of the states at
special points, lines or areas in the Brillouin zone and the
matrix-elements of the spin-flip part of the spin-orbit
coupling operator. We further calculate the skew-scattering
contribution to the anomalous Hall effect(AHE) in dilute
alloys based on a ferromagnetic host for the first time. A
systematic study of 3$\textit{d}$ impurities in bcc Fe, as
well as the non-magnetic hosts Pd, Pt and Au, allows us to
identify trends across the periodic table. In all our
calculations, we also observe a strong correlation between
the spin Hall effect and anomalous Hall effect in these
materials, which is of interest for the creation and
detection of strongly spin-polarized currents. A
Fermi-surface analysis of the contributions to the AHE
reveals a non-trivial, peaked behavior at small hot-spots
around spin-orbit lifted degeneracies. We then proceed to
the more complicated $\textit{L}$1$_{0}$-ordered alloy FePt
and address different kinds of disorder. We showcase the
power of our method by treating the very complicated
compounds Fe$_{x}$Mn$_{1-x}$Si and MnSi$_{1-x}$Ge$_{x}$,
based on the non-Fermi liquid manganese silicide (MnSi).
Finally, we also calculate the pure spin Hall effect for
4$\textit{d}$/5$\textit{sp}$ and
5$\textit{d}$/6$\textit{sp}$ impurities in fcc Ir and hcp Re
hosts. For the latter, we discover a strong dependence on
the electron's spin-polarization direction.},
keywords = {Dissertation (GND)},
cin = {PGI-1 / IAS-1},
cid = {I:(DE-Juel1)PGI-1-20110106 / I:(DE-Juel1)IAS-1-20090406},
pnm = {422 - Spin-based and quantum information (POF2-422)},
pid = {G:(DE-HGF)POF2-422},
typ = {PUB:(DE-HGF)11},
url = {https://juser.fz-juelich.de/record/171881},
}