Fig. 4: Selective excitation of the eigenmodes in the 7th flatband.

a, b Field distribution with three excitation sites near the center, which have a large overlap with the eigenmode C = 0. c, d Field distribution with three excitation sites that have a large overlap with the eigenmode C = 2. The excitation phase difference ϕ = 0 in a, c, and ϕ = 2π/3 in b, d. The radii of the colored dots are proportional to the field intensity on the lattice sites, with colors indicating the phases. The two figures in the middle are the numerically simulated field distributions of the corresponding eigenmodes.