Spin wave

General description


This experiment is intended to provide an insight into the physics of spin waves. Spin waves, which are also described by their quasiparticles, the magnons, in the context of the second quantization, are an important part of basic research in magnetism. Furthermore, they have the potential to make a contribution to energy saving as information carriers and in the storage of data in times of increasingly data space resources. In the experiment, the propagation characteristics of waves in thin magnetic films are investigated as a function of various parameters. In theory, a distinction is made between exchange-dominated and dipolar spin waves. In this experiment, the focus is on the latter, since they exhibit anisotropic and dispersive properties and thus open up a wide range of possible applications. The consideration of the associated dispersion relations of dipolar spin waves is therefore an important aspect. The dispersion essentially depends on the relative orientation of the sample magnetization and the spin wave wave vector. In the following it is assumed that the magnetization is always parallel to the film plane. The resulting dispersion relation at a magnetization aligned parallel to the wave vector shows a negative group velocity. This is the so-called magnetostatic reverse volume mode. If the magnetization is applied perpendicular to the wave vector, a dispersion relation with positive group velocity is obtained, which is called magnetostatic surface mode or Damon-Eshbach mode.
In this experiment the effects of different parameters on the propagation of spin waves in a YIG waveguide (Y3Fe5O12) shall be investigated.

 

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