Fractional Chern mosaic in supermoiré graphene

Abstract

We propose the realization of a fractional Chern mosaic: a state characterized by a spatially varying topological order. This state is enabled by a separation of length scales that emerges when three graphene sheets are sequentially rotated by a small twist angle. The resulting structure features not only conventional moiré lattices, but also a much larger supermoiré lattice. We demonstrate that a fractional Chern mosaic arises when electron correlations induce fractionalization locally on the moiré scale, while the pattern of fractionalization varies at the supermoiré scale.

5+11 pages