Transport via coupled states in a C60 peapod quantum dot

We have measured systematic repetitions of avoided crossings in low-temperature three-terminal transport through a carbon nanotube with encapsulated C-60 molecules. We show that this is a general effect of the hybridization of a host quantum dot with an impurity. The well-defined nanotube allows identification of the properties of the impurity, which we suggest to be a chain of C-60 molecules inside the nanotube. This electronic coupling between the two subsystems opens the interesting and potentially useful possibility of contacting the encapsulated molecules via the tube.