Berlin 2008 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 19: Spin Dynamics / Spin Torque I
MA 19.15: Vortrag
Mittwoch, 27. Februar 2008, 17:45–18:00, EB 301
Dynamic Vortex-Antivortex Interaction in a Single Cross-Tie Wall — •Karsten Kuepper1, Matthias Buess2, Joerg Raabe2, Christoph Quitmann2, and Juergen Fassbender1 — 1FZ Dresden-Rossendorf, Bautzner Landstr. 128, 01328 Dresden, Germany — 2Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
In a rectangular permalloy platelet one can find a stable micromagnetic configuration comprising two vortices and an antivortex, a so called single cross-tie wall. Such a single cross-tie wall can be understood as being a coupled micromagnetic system with three static solitons. Here we report on its magnetization dynamics including the vortex-antivortex interactions [1]. The spectrum of eigenmodes is investigated as well as the effect of different vortex core orientations. These are important for the magnetization dynamics because they determine the sense of rotation for the gyrotropic motion. Since three cores are present in total 23 = 8 configurations are possible. We find that different types of configurations lead to completely different dynamic behaviors. The origin is the dynamic coupling of the cores which is mediated by the exchange coupling through the adjacent domain walls. This coupling is significant and introduces unexpected effects, such as the quenching of gyrotropic motion for the antivortex in certain core configurations. The vortex dynamics can be used to identify the core configuration, which is not directly accessible to x-ray microscopy because of its limited spatial resolution.
[1] K. Kuepper et al., Phys. Rev. Lett. 99, 167202 (2007)