Indirect Moiré Superlattice Patterning of Monolayer Graphene

The electronic properties of a material can be manipulated by superimposing a spatially periodic superlattice potential. Initially explored in vertical semiconductor heterostructures and lithographically patterned two-dimensional electron gases, moiré patterning of superlattices at van der Waals (vdW) interfaces has emerged as a complementary route to engineered band structures. Although moiré patterns can reach smaller superlattice periodicities than practical with lithography, they can be non-uniform due to lattice reconstruction at the vdW interface. Furthermore, many of the moiré patterned superlattices explored thus far have hexagonal symmetry. Here we explore an indirect approach to moiré superlattice patterning by encapsulating monolayer graphene between dielectrics which would have a moiré pattern at their interface. The separation of the dielectric layers may mitigate moiré disorder arising from lattice reconstruction. Furthermore, indirect moiré patterns can be constructed by lattice mismatch or angular misalignment between dielectrics with a variety of point group symmetries. We comment on how this diversity of superlattice symmetries could pave the way to a variety of novel electronic phases.