The Unconventional Influence of a Nearby Molecule onto Transport of Single C_60 Molecule Transistor

We study the transport property of single C_60 molecular transistors with special focus on the situation that other molecules are in vicinity. The devices are prepared using electromigration and thermal deposition techniques. Pure single C_60 molecule transistors show typical coulomb blockade behavior at low temperature. When we increase the coverage of molecules slightly by extending the deposition time, the transport spectrum of devices displays a switching behavior in the general coulomb blockade pattern. We attribute this unconventional phenomenon to the influence from a nearby C_60 molecule. By analyzing this transport behavior quantitatively based on the parallel-double-quantum-dot model, the interaction from the nearby molecule is proved to be of capacity and tunneling coupling. Thermal stimulation is also applied to the device to investigate the effect of local charging environment variation on intermolecular interaction.