Capacitance Measurements of Rhombohedral Graphene/hBN Moiré Superlattice: Part I

Rhombohedral pentalayer graphene aligned to hexagonal boron nitride (R5G/hBN) has proven to be a rich system that hosts topological bands along with strong electronic correlations. Previous transport studies have revealed zero-field integer and fractional quantum anomalous Hall states when the displacement field is tuned such that the conduction electrons are pushed away from the R5G/hBN interface. In this talk, I will discuss capacitance measurements of R5G/hBN in this moiré-distant regime that probe the electronic compressibility of the system. Our measurements reveal a rich phase diagram of both topological and trivial insulating phases at fractional filling and zero magnetic field beyond what has been seen in transport. These results expand the previously known phase diagram and provide essential information for developing a better theoretical understanding of the system.