% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@PHDTHESIS{Buhl:863478,
      author       = {Buhl, Patrick Markus},
      title        = {{T}opological transport in non-{A}belian spin textures from
                      first principles},
      volume       = {197},
      school       = {RWTH Aachen},
      type         = {Dr.},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zetralbibliothek, Verlag},
      reportid     = {FZJ-2019-03532},
      isbn         = {978-3-95806-408-9},
      series       = {Schriften des Forschungszentrums Jülich. Reihe
                      Schlüsseltechnologien / Key Technologies},
      pages        = {VII, 158 S.},
      year         = {2019},
      note         = {RWTH Aachen, Diss., 2019},
      abstract     = {Recently, skyrmions attracted huge attention due to their
                      topological character which ensures surprisingly stable,
                      particle-like magnetic excitations on small scales with
                      distinctive dynamical properties. Their characteristic
                      transport signature—the topological Hall effect—has
                      become an established tool for detection of topologically
                      non-trivial ferromagnetic textures. However,this attribute
                      vanishes when considering degenerate antiferromagnetic
                      structures as theassociated emergent magnetic field is
                      spin-dependent. This thesis demonstrates the emergence of an
                      alternative transport signature in case of antiferromagnetic
                      skyrmion textures—the topological spin Hall effect.
                      Firstly, a computational scheme is developed which estimates
                      the topological spin Hall effect based on semiclassical
                      wave-packet dynamics. In the adiabatic limit, their
                      equations of motion allow to treat large-scale magnetic
                      textures on top of locally collinear, small-scale
                      Hamiltonians, here based on density functional theory.
                      Transport expressions are extracted by combination of the
                      equations of motion and the Boltzmann formalism. While the
                      analogous procedure is straightforward for ferromagnetic
                      materials, the wave-packet’s $\textit{SU}$(2)-nature,
                      caused by degenerate bands, results in additional spin
                      dynamics and non-abelian Berry curvatures which inhibit
                      direct transport evaluation. While the reciprocal-space
                      dynamics are treated on the Boltzmann level, the spin and
                      real-space dynamics are solved iteratively starting from
                      multiple initial positions. Evaluation of the traversed
                      paths results in integrated expressions for the topological
                      spin Hall effect. Sizable topological spin Hall responses
                      are predicted in simulations for the exemplary
                      Fe/Cu/Fe-trilayers and thin chromium layers when
                      artificially imprinting synthetic and intrinsic
                      antiferromagnetic skyrmions, respectively. The importance of
                      the non-abelian dynamics is demonstrated by large
                      differences relative to comparative calculations of
                      decoupled antiparallel ferromagnets. While the spin
                      evolution results in surprisingly homogeneous transport
                      modifications, the $\textbf{k}$-resolved intra-band overlap
                      has a particularly unpredictable distribution requiring
                      precise density functional theory calculations. Further
                      numerical thoroughness isrequired because of extreme
                      sensitivity with respect to small reciprocal-space
                      modificationssuch as slight Fermi energy changes.
                      Furthermore, the evolution of the $\textbf{k}$-dependent
                      transport and overlap properties is shown with respect to
                      thickness variations demonstrating rich tuning potential.
                      Conversely, multiple calculations modifying the
                      skyrmion-radius, -shape, and -density demonstrate the
                      topological invariance of the topological spin Hall effect.
                      Overall, the topological spin Hall effect is an interesting
                      phenomenon with rich application possibilities. Foremost, it
                      facilitates the discovery of the so far undetected
                      antiferromagnetic skyrmions, but also might provide
                      efficient spin-current generation as required in spintronic
                      applications. Alternatively, it could serve as read-out
                      mechanism of more complex devices like antiferromagnetic,
                      skyrmion-based racetrack memory. Hence, the developed
                      versatile and readily applicable computational scheme is a
                      great addition for future antiferromagnetics kyrmion
                      studies.},
      cin          = {IAS-1 / PGI-1 / JARA-FIT / JARA-HPC},
      cid          = {I:(DE-Juel1)IAS-1-20090406 / I:(DE-Juel1)PGI-1-20110106 /
                      $I:(DE-82)080009_20140620$ / $I:(DE-82)080012_20140620$},
      pnm          = {142 - Controlling Spin-Based Phenomena (POF3-142)},
      pid          = {G:(DE-HGF)POF3-142},
      typ          = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
      url          = {https://juser.fz-juelich.de/record/863478},
}