Spin wave standard problem » History » Version 15
Guru Venkat, 02/25/2015 09:09 AM
| 1 | 2 | Guru Venkat | h1. Proposal for a Standard Micromagnetic Problem: Spin Wave Dispersion in a Magnonic Waveguide |
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| 3 | 2 | Guru Venkat | G. Venkat, D. Kumar, M. Franchin, O. Dmytriiev, M. Mruczkiewicz, H. Fangohr, A. Barman, M. Krawczyk and A. Prabhakar |
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| 5 | 3 | Guru Venkat | online: "journal":http://dx.doi.org/10.1109/TMAG.2012.2206820, local preprint pdf (attachment:SW_standard_problem_Pre_print.pdf) |
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| 7 | 3 | Guru Venkat | {{toc}} |
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| 9 | 3 | Guru Venkat | h2. Motivation |
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| 11 | 11 | Guru Venkat | * The micromagnetic standard problems (www.ctcms.nist.gov/~rdm/stdplan.html) allow to compare the simulation results of different simulation tools and help finding bugs and errors. |
| 12 | 3 | Guru Venkat | * Here we propose a new standard problem that computes spin wave dispersion of a permalloy stripe using different micromagnetic packages |
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| 14 | h2. Summary |
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| 16 | * We propose a standard micromagnetic problem which involves a nanostripe of permalloy |
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| 17 | 5 | Guru Venkat | * 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. |
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| 19 | 4 | Guru Venkat | !SW_scaled.png! |
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| 21 | 3 | Guru Venkat | * Spin wave dispersion curves, relating frequency and wave vector, are obtained for wave propagation in different configurations |
| 22 | * Simulation results obtained using both finite element (Nmag) and finite difference (OOMMF) packages are compared against analytic results |
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| 24 | 5 | Guru Venkat | h2. Selected results |
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| 26 | The dispersion curves compared against the analytic equations (dotted lines). |
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| 28 | 1 | Guru Venkat | !Dispersions_scaled.png! |
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| 30 | 8 | Guru Venkat | h2. Supporting material |
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| 32 | 15 | Guru Venkat | # **The Nmag mesh** - The mesh file (nanowire.nmesh.h5) is generated using the open source meshing utility Netgen using the included geometry file (geom_1000.geo) |
| 33 | 13 | Guru Venkat | # **The Nmag simulation script** - The simulation script (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 |
| 34 | # **The Nmag post processing script** - The post processing script (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. |
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| 35 | # **The Makefile for the Nmag simulation** - This 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. |
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| 36 | # **README** - A README file (README.txt) describes the action of the above Makefile |
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| 37 | 14 | Guru Venkat | # **The OOMMF simulation scripts** - The relaxation script (attachment:OOMMF_static.mif) and the dynamics script (attachment:OOMMF_dynamics.mif) should help in setting up an OOMMF simulation to obtain dispersion curves. |
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| 39 | All the files are included in this zip file (attachment:spin_wave_dispersion_standard_problem.zip) |