Engineering Correlated Physics in Two-Dimensional Moire Superlattices

Synopsis

Van der Waals heterostructures of atomically thin crystals offer an exciting new platform to design novel electronic and optical properties. In this talk, I will describe a general approach to engineer correlated physics-archive using moire superlattice in two dimensional heterostructures. One example is the tunable Mott insulator realized in the ABC trilayer graphene (TLG) and hexagonal boron nitride (hBN) heterostructure with a moiré superlattice, where the moiré leads to narrow electronic minibands and allows for the observation of gate-tunable Mott insulator states at 1/4 and 1/2 fillings. In addition, signatures of superconductivity are observed at low temperature near the ¼ filling Mott insulator state in the TLG/hBN heterostructures. Another example is the WS2/WSe2 heterostructure, where the moire superlattice leads to flat exciton subbands and emerging excitonic transitions.