Proposal for a Standard Micromagnetic Problem: Spin Wave Dispersion in a Magnonic Waveguide¶

G. Venkat, D. Kumar, M. Franchin, O. Dmytriiev, M. Mruczkiewicz, H. Fangohr, A. Barman, M. Krawczyk and A. Prabhakar

online: journal, local preprint pdf (SW_standard_problem_Pre_print.pdf)

• Table of contents
• Proposal for a Standard Micromagnetic Problem: Spin Wave Dispersion in a Magnonic Waveguide
  • Motivation
  • Summary

Motivation¶

• The micromagnetic standard problems allow to compare the simulation results of different simulation tools and help finding bugs and errors.
• Here we propose a new standard problem that computes spin wave dispersion of a permalloy stripe using different micromagnetic packages

Summary¶

• We propose a standard micromagnetic problem which involves a nanostripe of permalloy
• The magnetization dynamics is studied and methods to extract features from simulations are described. The image below shows spin waves propagating as a function space and time.
  
• Spin wave dispersion curves, relating frequency and wave vector, are obtained for wave propagation in different configurations
• Simulation results obtained using both finite element (Nmag) and finite difference (OOMMF) packages are compared against analytic results

Selected results

1. Supporting material

1. The mesh - The mesh file (attachment:nanowire.nmesh.h5). It has been generated using the Examesh utility (attachment:examesh.zip) which can be used for generating the mesh for a cuboid structure.
2. The simulation script - The simulation script (attachment:run.py) has details of the simulation. The comments in it should be self explanatory. Notice that it uses the HLib library for compressing the BEM matrix generated during the simulation
3. The post processing script - The post processing script (attachment:post_process.py) generates the spin wave space-time and dispersion plots from the simulation data. It is assumed that NUmpy and matplotlib are both available.
4. The Makefile - This Makefile (attachment:Makefile) should run the entire simulation and then generate the dispersion curves. We strongly suggest this sort of approach because it reduces manual effort and the chances of errors.
5. README - A README file (attachment:README.txt) describes the action of the Makefile

All the files are included in this zip file (attachment:spin_wave_dispersion_standard_problem.zip)