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@INPROCEEDINGS{Freimuth:906128,
      author       = {Freimuth, Frank},
      title        = {{S}pin-orbit torques from first principles: {C}ollinear
                      magnets, noncollinear magnets, temperaturedependence},
      reportid     = {FZJ-2022-01244},
      year         = {2022},
      abstract     = {Spin-orbit torques (SOTs) in magnetic bilayers composed of
                      a 5d transition metal layer and aferromagnetic layer can
                      serve as a competitive alternative to the Slonczewski
                      spin-transfer torque inspin-valves and magnetic tunnel
                      junctions in order to realize MRAM devices. Based on our
                      first -principles approach to compute the SOT, we will first
                      discuss the SOT in Co/Pt and Mn/W magneticbilayers [1,2]. A
                      particular focus will be on the role of the spin-currents
                      that contribute to these torques.We will show how the
                      understanding of the SOT in these ferromagnetic bilayers may
                      be transferred tothe SOT in antiferromagnetic bilayers such
                      as FeRh/W[3]. A necessity to obtain the SOT is thebreaking
                      of space inversion symmetry. While magnetic bilayers such as
                      Co/Pt and Mn/W exhibitstructural breaking of inversion
                      symmetry, half Heusler compounds such as PtMnSb display
                      brokeninversion symmetry in the bulk. We will show that the
                      SOT in half Heuslers may reach magnitudescomparable to
                      magnetic bilayers and is very sensitive to strain [4]. Next,
                      we will discuss that thecombination of structural inversion
                      asymmetry and noncollinear magnetism leads to
                      additionalmechanisms of the SOT. In particular, we will
                      discuss Co/Cu/Co trilayers, where spin currentsgenerated by
                      in-plane current at one FM/NM interface can be used to
                      switch the other FM [5]. Despitethe absence of heavy metals
                      with strong spin-orbit coupling the SOTs in Co/Cu/Co
                      trilayers are sizable.The SOT in the top FM can be tuned by
                      the magnetization direction of the bottom FM. We will
                      showthat in noncollinear magnets SOT and current-induced
                      Dzyaloshinskii-Moriya interaction areintertwined, such that
                      both effects need to be considered at the same time in order
                      to obtain results thatsatisfy the Onsager-reciprocity
                      relations [6]. Finally, we will discuss the temperature
                      dependence ofSOTs found in experiments, which is often not
                      yet well understood by the theoretical models. We
                      willdiscuss our formalism development for the calculation of
                      the magnonic contribution to the SOT andpresent results for
                      this magnonic SOT in the Rashba model [7].[1] F. Freimuth et
                      al., PRB 92, 064415 (2015)[2] F. Freimuth et al., PRB 90,
                      174423 (2014)[3] F. Freimuth et al.,
                      https://arxiv.org/abs/2102.10598[4] F. Freimuth et al., PRB
                      103, 224414 (2021)[5] F. Freimuth et al., PRB 98, 024419
                      (2018)[6] F. Freimuth et al., PRB 102, 245411 (2020)[7] F.
                      Freimuth et al., PRB 104, 094434 (2021)},
      month         = {Feb},
      date          = {2022-02-22},
      organization  = {Group Seminar,
                       Martin-Luther-Universität
                       Halle-Wittenberg (Germany), 22 Feb
                       2022},
      subtyp        = {Invited},
      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          = {5211 - Topological Matter (POF4-521)},
      pid          = {G:(DE-HGF)POF4-5211},
      typ          = {PUB:(DE-HGF)31},
      url          = {https://juser.fz-juelich.de/record/906128},
}