Guilin Sun
Ansys Employee

Thank you for sharing the papers. To compare with any 3rd party tools, please be careful as you may not know the exact details of simulations. please refer this post: https://forum.ansys.com/forums/topic/ansys-insight-why-my-simulation-result-is-different-from-published-paper-or-experiment/

For the 2nd case, there is a 10nm thin layer, and a 20nm gap. They might be important: how many meshes do they have? 50 cells per wavelength might not be enough, since the metal is lossy, and its skin depth is small. The mesh should well resolve the skin depth. For conformal variant 1 it works well for finer mesh. However we do not know how fine the mesh should be to get better result.  Please also do a convergence testing. Please note that when the mesh is fine, make sure the PML is thick enough to absorb em waves.

One more question: is there any substrate below the 100nm Au ?  I believe experimentally it should have.

Please force the mesh symmetric in the plane of the two circles.

 

Happy New Year!