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MA: Fachverband Magnetismus
MA 5: Spincaloric Transport
MA 5.6: Talk
Monday, March 14, 2011, 12:15–12:30, HSZ 04
Numerical studies of thermally driven domain wall dynamics — •Denise Hinzke, Ulrike Ritzmann, and Ulrich Nowak — Universität Konstanz, 78457 Konstanz
The understanding of the influence of thermal properties of magnetic materials on its magnetic behaviour opens new perspectives for the control of magnetic domains and domain walls. Recently it has been demonstrated that spatial temperature gradients can lead to spin accumulation via the so-called spin-Seebeck effect [1]. For the latter case two kinds of spin currents can exist in a ferromagnet; a spin polarised charge current due to electron motion or a pure angular momentum current driven by spin waves. For the latter one leads to pure thermo-magnetic effects without any electron currents involved.
Two different approaches for the simulation of coupled thermo-magnetic properties are introduced: the stochastic Landau-Lifshitz-Gilbert equation, applied to atomistic spin models, and the Landau-Lifshitz-Bloch equation describing the dynamics of the thermally averaged spin polarisation on micromagnetic length scales [2]. Both approaches are applied to study domain wall dynamics driven by spin currents caused by a temperature gradient. We find new type of domain wall dynamics, where pure spin currents following from a temperature gradient drag a domain wall into the hotter region.
We acknowledge financial support by the DFG through SFB 767. [1] K. Uchida et al, Nature 455, 778 (2008). [2] N. Kazantseva et al, Phys. Rev. B 77, 184428 (2008).