Dresden 2009 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 40: Poster II: Bio- and Molecular Magnetism (1-9); Magnetic Coupling Phenomena/Exchange Bias (10-15); Magnetic Particlicles and Clusters (16-29); Micro and Nanostructured Magnetic Materials (30-51); Multiferroics (52-64); Spin Injection in Heterostructures (65-67); Spin-Dyn./Spin-Torque (68-93); Spindependent Transport (94-108)

MA 40.78: Poster

Freitag, 27. März 2009, 11:00–14:00, P1A

Spin-wave excitation in Permalloy by oscillating pinned domain walls — •Christopher Rausch, Sebastian Hermsdörfer, Helmut Schultheiß, Sebastian Schäfer, Philipp Pirro, Britta Leven, and Burkard Hillebrands — FB Physik und Landesforschungszentrum OPTIMAS, Erwin-Schrödinger-Str. 56, TU Kaiserslautern, 67663 Kaiserslautern, Germany

This poster presents a new mechanism for the spin-wave excitation. The excitation of spin waves by oscillating pinned domain walls is an alternative approach to the well-known excitation via an antenna or, as another example, via vortex-anti-vortex-annihilation. The investigations have been carried out using micromagnetic simulations (LLG-code). The basic idea of the mechanism is to deflect a pinned domain wall out of its equilibrium position within the limits of the domain wall pinning. The following relaxation caused by the pinning potential which is driving the wall back towards the equilibrium position occurs as a damped oscillation with characteristic eigenfrequency. In case that the domain wall is excited by an external field with this eigenfrequency, a "steady-state" oscillation forms out with the eigenfrequency and an amplitude determined by the energy balance between the dissipation processes due to damping and the external triggering by the applied field. The energy pumped into the system by the external field leads not only to the compensation of the damping but also to the radiation of spin waves.

Financial support by the DFG within the SPP1133 is gratefully acknowledged.