Cavity simulation with Mumax-cQED

[Vivek]

I am Vivek Kumar, currently working on simulating photon–magnon coupling in hybrid cavity–magnon systems. I have a few technical questions regarding the recommended methodology:

 

• Brms : What actually is Brms of cavity in its electromagnetic simulations ?
• Simulation Scaling: Since simulating millimetre-scale samples directly is not feasible, what is the correct way to downscale the system? When the geometry is scaled down, how should the imported cavity magnetic field (Brms​) be adjusted (in its spatial scale and/or magnitude) to preserve the coupling physics?
• Field Extraction Frequency: At which frequency should the cavity's magnetic field distribution (Brms​) be extracted from an EM solver like COMSOL — exactly at resonance, or different than resonance ?
• Field Magnitude Scaling: When I import the Brms​ field of cavity designed in comsol, the magnetization vector aligns towards Brms field which prevents coupling , so to observe coupling I have to manually scale down the magnitude of Brms​ by a factor of 10-100. Is this manual scaling correct, or is there a formal normalization procedure for Brms​?
• Brms​ vs. Bext​: In the code examples, Bext ​ and Brms​ seem to be proportional, with a scaling factor around 1e6. Could you please explain the physical basis for this relationship ?

I would greatly appreciate your guidance on these points, as it will help ensure that the simulations are both physically accurate and methodologically sound.

Thanks