Berlin 2012 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 50: Joint Session "Spincaloric Transport" (jointly with TT)

MA 50.8: Vortrag

Freitag, 30. März 2012, 11:15–11:30, EB 301

Domain Wall Motion by the Magnonic Spin Seebeck Effect — •Ulrike Ritzmann, Denise Hinzke, and Ulrich Nowak — Universität Konstanz

In the last years it was demonstrated that in ferromagnetic materials spatial temperature grandients can lead to spin accumulation [1], even in magnetic insulators [2]. In this context, it is important to note that in addition to a spin polarized charge current also a chargeless angular momentum current driven by spin waves can exist.

Here, we propose the existence of domain wall (DW) dynamics driven by magnonic spin currents due to temperature gradients. To get some insight into this effect we introduce two different approaches: the stochastic Landau-Lifshitz-Gilbert equation, applied to spin models, and the Landau-Lifshitz-Bloch equation describing the dynamics of the thermally averaged spin polarization on micromagnetic length scales. We show that these approaches describe this new type of DW motion, where chargeless spin currents following from a temperature gradient drag a DW into the hotter region [3]. Furthermore, for a better understanding of the relevant length scales, we investigate the propagation and frequency range of thermally induced magnons.

We acknowledge financial support by the Deutsche Forschungsgemeinschaft through Schwerpunktprogramm SpinCaT.

[1] K. Uchida et al., Nature 455, 778 (2008).

[2] K. Uchida et al., Nat. Mater. 9, 894(2010).

[3] D. Hinzke and U. Nowak, Phys. Rev. Lett. 107, 027205(2011)