A recent study from the Columbia University labs of James Hone (mechanical engineering) and Cory Dean (physics) demonstrates a new way to tune the properties of two-dimensional (2-D) materials simply by adjusting the twist angle between them. The researchers built devices consisting of monolayer graphene encapsulated between two crystals of boron nitride and, by adjusting the relative twist angle between the layers, they were able to create multiple moiré patterns.
Moiré patterns are of high interest to condensed matter physicists and materials scientists who use them to change or generate new electronic material properties. These patterns can be formed by aligning boron nitride (BN, an insulator) and (a semimetal) crystals. When these honeycomb lattices of atoms are close to alignment, they create a moiré, a nanoscale interference pattern that also looks like a honeycomb. This moiré superlattice alters the quantum mechanical environment of the conducting electrons in the graphene and therefore can be used to program in the observed electronic properties of the graphene. Read more here.