  Graphene/hexagonal boron nitride (hBN) moir\'e superlattices have attracted
interest for use in the study of many-body effects and fractal physics in Dirac
fermion systems. Many exotic transport properties have been intensively
examined in such superlattices, but previous studies have not focused on
single-carrier transport. The investigation of the single-carrier behavior in
these superlattices would lead to an understanding of the transition of
single-particle/correlated phenomena. Here, we show the single-carrier
transport in a high-quality bilayer graphene/hBN superlattice-based quantum dot
device. We demonstrate remarkable device controllability in the energy range
near the charge neutrality point (CNP) and the hole-side satellite point. Under
a perpendicular magnetic field, Coulomb oscillations disappear near the CNP,
which could be a signature of the crossover between Coulomb blockade and
quantum Hall regimes. Our results pave the way for exploring the relationship
of single-electron transport and fractal quantum Hall effects with correlated
phenomena in two-dimensional quantum materials.
