Unfortunately, spatially-varying magnetic permeability is not available. Current supported material models can be found:
https://optics.ansys.com/hc/en-us/articles/360034394734-Advanced-and-custom-optical-material-models-in-FDTD-and-MODE
The paramagnetic material can handle diagonal permeability but not spacially-carying. It can be very challenge to implement it with pixel-wise method.
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