Flat band localization in 1D moiré bilayer photonic crystals with staggered potential

Moiré photonic crystals exhibit a variety of exciting phenomena, including flatband localization. In bilayer moiré photonic crystals, activating flatband localization often requires precise tuning of various structural parameters, which may limit its experimental realization and applications. In this work, we discuss one-dimensional moiré bilayer photonic crystals with staggered potential introduced into each layer. Moiré patterns were formed by slightly differentiating the lattice periods of the top and bottom grating layers, which were double-periodically modulated for introducing the staggered potential. We found that the staggered potential helps in inducing flatband localization in a wider parameter space. We identified the magnitude of the staggered potential as a handy tuning parameter for the manipulation of photonic moiré bands and their wave functions. Our finding here will accelerate the nano-/microcavity formation through moiré physics.