RESONANT-TUNNELING THROUGH DISCRETE ELECTRONIC LEVELS OF A C-60 MOLECULE IN THE PRESENCE OF CHARGING EFFECTS

We have conducted tunneling spectroscopy studies for isolated C-60 mol ecules in the double barrier tunnel junction configuration. The tunnel ing current-voltage (I-V) and dI/dV vs. V spectra of these molecules e xhibit rich structures resulting from both resonant tunneling through the discrete levels and single electron charging effects. In particula r, we observe degeneracy lifting within the molecular orbitals, probab ly due to the Jahn-Teller effect and local electric fields. Theoretica l fits, performed using the ''orthodox'' model for single-electron tun neling modified to account for the discrete level spectrum of C-60, ag ree well with our data.