Berlin 2012 – scientific programme

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AGjDPG: Arbeitsgruppe junge DPG

AGjDPG 6: PhD Student Symposium: Spintronics on the Way to modern Storage Technology I

AGjDPG 6.5: Topical Talk

Thursday, March 29, 2012, 11:30–12:00, BH 243

Spin wave propagation and excitation, microwave assisted switching and non-linear magnetic resonance — •Georg Woltersdorf, Hans G. Bauer, and Christian H. Back — Universität Regensburg, Regensburg, Germany

The control of the propagation properties of spin waves is essential for the successful implementation of magnon based logic devices. In addition since large excitation amplitudes are needed it is desirable to thoroughly understand the non-linear magnetization dynamics in such structures.

We use time resolved Kerr microscopy to study magnetic excitations on a sub-micron length scale. In doing so the spin wave propagation in magnetic wires and microwave assisted switching behavior in magnetic elements is studied. In addition we use X-ray magnetic circular dichroism experiments to determine precisely the number of magnons that are excited in Permalloy films. We show that commonly used models for non-linear resonance are actually not applicable at low bias fields. A simple non-linear model allows us to find the correct threshold field and the associated critical modes. This analysis explains our experimental findings and agrees with micro-magnetic simulations.