Orbital magnetism in twisted multi-layer graphene with two moiré interfaces

Recent years have seen an intense interest in the field of moiré materials formed by stacking layers of 2D crystals that have a small difference in their lattice constant or orientation. 2D moiré systems often show both strong electronic correlations and non-trivial band topology leading to novel properties such as quantum anomalous Hall effect, superconductivity and emergent orbital ferromagnetism. Here, we design heterostructures of graphene layers composed of two moiré interfaces. We study the system by varying the relative stacking chirality of the moiré interfaces along with parameters such as external field and strain. Specifically, we focus on the variation of topological states and orbital magnetism in these systems as a function of these parameters. Our results show that multi-moiré systems provide an attractive platform for a variety of applications owing to their novel and tunable electronic properties.