Fabrication and characterization of quantum dot devices based on tetralayer graphene/hexagonal boron nitride heterostructures

We report on low temperature carrier transport property of quantum dot (QD) devices based on hexagonal boron nitride-encapsulated tetralayer graphene heterostructures. In the device with single dot geometry, we demonstrate a stochastic Coulomb blockade, suggesting formation of multiple dots coupled each other in series/parallel. Under a perpendicular magnetic field, the overlapping Coulomb diamonds are lifted at zero bias voltage and the charging energy is decreased. These imply the suppression of multiple dots behavior. Our results pave a way toward the investigation of interlayer correlation on single electron transport in few-layer graphene QDs.