Berlin 2015 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 9: Spin Excitations/Spin Torque
MA 9.12: Vortrag
Montag, 16. März 2015, 18:30–18:45, H 0112
Vortex Core Motion driven by Thermal Spin Transfer Torque — •Michael Vogel1, Jean-Yves Chauleau1, Claudia Mewes2, Tim Mewes2, and Christian Back1 — 1Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Regensburg, Germany — 2MINT Center / Depeartment of Physics and Astronomy, University of Alabama, Tuscaloosa, AL, USA
The dynamical properties of spin caloric devices play a key role in their design and functionality. Especially the estimation of the required temperature gradients is essential for a successful development of new spin caloritronic applications and experiments. We report on theoretical investigations of magnetic vortex motion driven by thermal spin transfer torque for static and time dependent temperature gradients. The magnetization dynamic of the vortex core is well described by the Landau-Lifshitz-Gilbert equation including the adiabatic and non-adiabatic spin transfer torque term [S. Zhang and Z. Li, Phys. Rev. Lett 93, 127204 (2004)]. Using the Onsager relations within a three current model [S.D. Brechet, and J.-P. Ansermet, Phys. Status Solidi RRL 5, No. 12, 423*425 (2011); K.M.D. Hals, A. Brataas, and G.E.W. Bauer, Solid State Com. 150, 461465 (2010)] one can write the involved current density as a spin polarization factor times a current density derived from the temperature gradient which is determined by experimental measurements in combination with finite element calculations. We report on the dynamic behavior of such systems and the importance of the interplay of the spatial and temporal shape of the heat gradient in combination with the geometry of the magnetic structure.