Hi Dr Sun:
    Thank you very much for your quick response. I know it is a very advanced topic and you also may not have an idea, but I am just curious if I can get help from other channels (for e.g, not in this forum)? Because this would be really important in my research😊.

    Since Lumerical gives users this flexibility to modify the update equations, there maybe some of your technical people have an answer about it? Modifying the equation for surface conductivity should be very simple if this functionality is enabled (like electric fields). I simply wish to know if it is feasible before I started trying on my own. I read all the related articles regarding materal plug-in by Lumerical, but cannot find the solution by myself😢.

    Hope to have your reply!