Berlin 2012 – scientific programme

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MA: Fachverband Magnetismus

MA 51: Spin Excitations/ Spin Torque

MA 51.4: Talk

Friday, March 30, 2012, 10:15–10:30, H 1012

Domain Wall Torques from First Principles — •Frank Freimuth, Yuriy Mokrousov, and Stefan Blügel — Peter Grünberg Institut & Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

We present first-principles calculations of the adiabatic and non-adiabatic (NA) torques on domain-walls (DW) in bulk Fe, Co, Ni, FePd and FePt. Our calculations take into account both disorder and the spin-orbit interaction (SOI). The relation between the Gilbert damping and the NA torque is discussed. It has been shown experimentally [1] that additional SOI-mediated torques occur in asymetrically interfaced magnetic layers and suppress the Walker breakdown. The underlying mechanisms of these SOI-driven torques are investigated for Co/Pt slabs. It is shown that – in analogy to anomalous Hall and spin Hall effects – intrinsic [2,3] and extrinsic [4] contributions to the various torques can be distinguished and sometimes are of similar size. Additionally, we briefly describe our computational method [5,6], discussing particularly the use of the Wannier interpolation technique and the treatment of disorder. This work is supported by the HGF-YIG grant VH-NG-513.

[1] I. M. Miron et al., Nature Materials 10, 419-423 (2011)

[2] H. Zhang et al., Phys. Rev. Lett. 106, 117202 (2011)

[3] F. Freimuth et al., Phys. Rev. Lett. 105, 246602 (2010)

[4] J. Weischenberg et al., Phys. Rev. Lett. 107, 106601 (2011)

[5] F. Freimuth et al., Phys. Rev. B 78, 035120 (2008)

[6] www.flapw.de