The frequency different of SW dispersion relation in Mumax and OOMMF

[Tianyu Yang]

Hi, I am trying to reproduce a previous OOMMF simulation result using Mumax. The simulation involves exciting spin waves in a 6000 nm × 500 nm waveguide using a sinusoidal microwave field localized at the central 20 nm region, followed by extracting the dispersion relation of the spin waves via 2D FFT. 

However, during the reproduction process, I noticed that the dispersion relation obtained from Mumax shows frequencies approximately 1 GHz lower than those from OOMMF, even though I have used nearly identical settings (geometry, material parameters, excitation field, ...). 

Could someone give me some insight into potential causes for this difference? Thank you for your time and help!

Best regards,

Tianyu

[Josh Lauzier]

Hi,

Are there any actual differences between the two scripts? I would expect them to be essentially identical, unless there is some actual difference. My most likely guess is that something is set differently between the scripts by accident. 
You can try posting both scripts, it may make it easier to spot a difference. Although I can't promise, I am much less familiar with OOMMF myself, I find MIF files hard to follow.

There are some slight differences between how OOMMF and Mumax implements things (for instance how they do periodic boundary conditions, if I recall). But generally they are very very small unless a problem is very sensitive like hysteresis.

Best,
Josh L.

[Tianyu Yang]

Dear Josh. L,

Thanks for your reply. I posted script of mumax and dispersion relation  before, but I found that it wasn't displayed on the forum, so I'll send it again to make sure you can see it. We can see the difference of approximately 1 GHz from the two figures.

Tianyu

[啊伟]

Dear Tianyu Yang

I'm currently studying spin waves and drawing dispersion relation graphs. However, I have tried many methods but still haven't been able to obtain the correct dispersion relation. Today, I searched for related posts about dispersion relations on the mumax forum. I noticed that you previously showed a script related to dispersion relations on the forum. So here, I sincerely request that you could send me a script for drawing dispersion relations. This will be of great help to my research.

best

mengsv

[纪家清]

Dear mengsv,

In the article with DOI:10.1016/j.cpc.2019.06.023, titled "MuFA (Multi-type Fourier Analyzer): A tool for batch generation of MuMax3 input scripts and multi-type Fourier analysis from micromagnetic simulation output data," a Python software package is introduced for post-processing data to obtain dispersion curves. I am currently using this package to plot dispersion curves, and perhaps you could also try utilizing it.

best

Ji JiaQing

[啊伟]

dear sir  

  i download that python package,but i met some problems using it,and i don not get any useful information about how to use it ,so here i want ask you about how to use it .

this is my e-mail address 31875...@qq.com  

best mengsv