Micromagnetic simulations of absoption spectra

TL;DR

This paper enhances a numerical method for simulating magnetic spin wave absorption spectra, enabling faster calculations of energy absorption in ferromagnetic bodies of arbitrary shape under various magnetic fields.

Contribution

It introduces significant speed improvements and extends the method to calculate energy absorption in complex geometries with static and dynamic magnetic fields.

Findings

Absorption spectra for vortex states in thin discs, rings, and slabs are computed.

Most strongly excited resonance modes are identified.

Method allows analysis of arbitrary-shaped ferromagnetic bodies.

Abstract

Further development of a previously introduced method for numerically simulating magnetic spin waves is presented. Together with significant improvements in speed, the method now allows one to calculate the energy absorbed by the various modes excited by a position- and time-dependent H1 field in a ferromagnetic body of arbitrary shape in the presence of a (uniform or non uniform) static H0 field as well as the internal exchange and anisotropy fields. The method is applied to the case of the single vortex state in a thin disc, a ring, and various square slabs, for which the absorption spectra are calculated and the most strongly excited resonance modes are identified.