Origin of nanomechanical motion in a single-C60transistor

Abstract

We present a van der Waals density functional study of a negatively charged C${}_{60}$ on a Au(111) surface to investigate the nanomechanical motion in a single-molecular transistor [Park et al., Nature 407, 57 (2000)]. We found that the position of C${}_{60}$ is shifted away from the electrode surface when C${}_{60}$ is negatively charged because of the larger contribution from the Pauli repulsion between C${}_{60}^{\ensuremath{-}}$ and substrate than that from the attractive interaction with the image charge induced in the substrate. Implication to the Franck-Condon blockade is also discussed.