Moiré pattern
= Moiré pattern
{wiki}
A <Moiré pattern> is a large-scale modulation produced by superposing similar periodic structures. Two identical two-dimensional lattices rotated by a small angle $\theta$ have geometric period $L=a/[2\sin(\theta/2)]\simeq a/|\theta|$ in the usual matching geometry. In layered crystals this modulation can act as an electronic <superlattice>; the actual bands additionally depend on interlayer coupling and orbital structure.