STT Couplings

[Frosch]

Hello, everyone. I’m interested in exploring couplings in STT phenomena in Mtj. I’d like to know if this is possible in Mumax3.
For example: a coupling of a free layer -> barrier -> fixed layer -> barrier -> fixed layer.
If this is possible, how would I specify the parameters if I wanted the fixed layers to be different, for example?

Thank you for your attention,

Kawan

[Josh Lauzier]

Hi,

By default, mumax only has one fixed layer. You'd have to modify the source code for multiple. The best you can do is to pick some fixed layer and J that properly represents the net effect of the two layers. Also, note that mumax does not explicitly model the fixed layer, with the built in fixed layer feature. It's implicit. Depending on what you mean by coupling, this may or may not be an issue (you can adjust the fixed layer dynamically).

Depending on what exactly you want to study, you may be able to accomplish something by simply modeling 3 layers as normal magnetic materials, and then setting appropriate J/custom fields etc. That wouldn't be using the built in fixed layer features at all, you'd just be setting the layers just like any other magnetic material via regions.

Best,
Josh L.