The scheme of the simulation and the magnetic field results. Since (a) and (c) are non-resonant, the same frequency as (b) was chosen to observe the magnetic field. For other samples, the magnetic field at the frequency of maximum SE is shown. The left side is a scheme of each comparison. Starting from the gray dotted line (x = 0), three yoz slices are selected along the x direction. The slices represent the three positions of the most central unit (center position of the unit: x = 0 mm, 1/4 position of the unit: x = 13.25 mm, boundary position of the unit: x = 26.5 mm).