We report on the observation of periodic conductance
oscillations near quantum Hall plateaus in suspended graphene
nanoribbons. They are attributed to single quantum dots that
are formed in the narrowest part of the ribbon, in the
valleys and hills of a disorder potential. In a wide flake
with two gates, a double-dot system's signature has been
observed. Electrostatic confinement is enabled in single-
layer graphene due to the gaps that are formed between the
Landau levels, suggesting a way to create gate-defined
quantum dots that can be accessed with quantum Hall edge
states.
