Fig. 1: Strongly coupled photonic moiré superlattices.

a Picture of the photonic moiré superlattice. Two honeycomb lattices of dielectric resonator quasi-atoms (red and blue) are overlaid with twist-angle θ. The primitive unit cell in the right panel is marked with the red rhombus and contains 28 quasi-atoms. b Schematic illustration of the strong coupling regime of the moiré superlattice. As the interlayer couplings exceed the intralayer couplings, we find topological flat bands at large twist-angles. This feature is in direct contrast with the weak coupling regime, where flat bands appear only at the magic angles. See sections S14–18 in Supplementary Materials for the tunability of the interlayer couplings as a function of the refractive index and the twist-angle