Regensburg 2016 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 48: Poster Session II

MA 48.6: Poster

Donnerstag, 10. März 2016, 15:00–18:00, Poster B1

A General Analytic Description of the Ferromagnetic High Frequency Susceptibility — •Benjamin Zingsem, Michael Winklhofer, Ralf Meckenstock, and Michael Farle — Faculty of Physics and Center for Nanointegration (CENIDE), University Duisburg-Essen, 47057 Duisburg, Germany

We present a general analytic solution of the ferromagnetic high frequency susceptibility tensor in ferromagnetic systems with arbritrary free energy landscapes. In contrast to conventional approaches found throughout literature, we do not solve the Landau-Lifshitz-Gilbert-equation as a linear system of equations. Instead we employ the jacobian of the system in the perturbation to obtain the tensor with the well known Polder Ansatz. Thus we do not need to make assumptions on the entries of the tensor and the form of the free energy is left arbritray. This complete tensor allows for accurate and fast calculations of the high frequency susceptibility as a function of the applied field angle and amplitude as well as the frequency or any other physical parameter. Furthermore it allows for the description of asymetric lineshapes as well as lineshapes in non extremal magnetic directions. We also tackle the problem of finding the equilibrium states of the magnetization that are necessary in the calculation of the tensor in an unconventional way, suggesting a trajectory dependent second order newton algorithm. In addition to this we are able to calculate the magnon dispersion in reciprocal space as a density function, by applying the Suhl ansatz and including the diploar and the exchange contibution in the energy landscape.