Figure 5: Diagram for two-step model for rotation of C60 by pulse bias.
From: Switching Molecular Orientation of Individual Fullerene at Room Temperature
The first step is a weakening process in which the bonds between the C60 and the Si atoms are weakened or broken due to the electronic excitation of the tunneling electrons. The second step is that the low energy electrons bombard the weakened C60 to make this molecule rotate by certain degree.
