▎ 摘　　要

The metallic tip of a scanning probe microscope operated at a temperature of 1.7 K is used to locally induce a potential in a graphene nanoribbon. Images of the conductance through the device as a function of tip-position show that two centers of enhanced conductance are formed inside the structure. By applying a linescan-technique, it can be demonstrated that these two features correspond to two charge localizations, exhibiting the characteristics of quantum dots. Scanning gate microscopy allows us to characterize them with high resolution both in real space and as a function of energy. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4742862]