Moiré effects in twisted graphene/graphite heterostructures

Moiré vdW heterostructures often host flat and isolated electronic bands which lead to strongly correlated states including superconductivity and magnetism. Ultra-thin twisted graphene heterostructures assembled from monolayer and bilayer constituents have been studied extensively over the past few years, but it is unknown what types of moiré effects emerge in the limit of bulk graphite (≥10 layers). We perform transport measurements of dual gated twisted monolayer graphene-graphite devices and find that the resulting two-dimensional surface moiré potential fundamentally changes the electronic properties of the entire structure. At low magnetic fields, we observe a single resistive peak that moves in an unusual zig-zag trajectory as a function of the top and bottom gate voltages. We observe a similar zig-zag evolution of quantum oscillations emerging at higher fields, which differ substantially depending on which gate is tuned. These measurements indicate that doping of the entire bulk graphite oscillates periodically as the moiré surface bands are filled. The unique properties of these moiré/bulk hybrid structures derive from the semimetallic nature of graphite, establishing a new class of moiré materials with mixed dimensionality.