Regensburg 2016 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 48: Poster Session II

MA 48.1: Poster

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

Multi-Scale Magnetic Vortex Core Switching — •Andrea De Lucia, Mathias Kläui, and Benjamin Krüger — Johannes Gutenberg Universität, Mainz, Germany

Simulations of magnetization dynamics in a multi-scale environment enable rapid evaluation of the Landau-Lifshitz-Gilbert equation in a mesoscopic sample with nanoscopic accuracy in the regions where such accuracy is needed. Here a multi-scale magnetization dynamics simulation scheme was developed and applied to systems with special spin structures and properties. To achieve this, the MicroMagnum simulator was used as a starting point and then expanded to include a multi-scale solving routine. The software selectively simulates different regions of a ferromagnetic sample according to their properties in order to employ the most suitable discretization and model for each. The method was used to investigate the effect of unipolar magnetic pulses for reliable switching of the core of a magnetic vortex. The switching was simulated for a Permalloy disk with a radius of 100 nm. The parameter range for switch of this device is shown. The core switching is mediated by the creation of a vortex-antivortex pair and the following annihilation of the original vortex with the antivortex. This process can be shown with unprecedented accuracy due to the multi-scale nature of the simulator. The presented results show that magnetic vortices can be reliably switched between two energetically degenerate, stable, polarization states by pulses with certain combinations of width and intensity that we determine with an unprecedented accuracy due to the multi-scale approach.