Pair tunneling and shot noise through a single molecule in a strong electron-phonon coupling regime

We investigate the electronic transport through a single molecule in a strong electron-phonon coupling regime. Based on a particle-hole transformation, which is made suitable for a nonequilibrium situation, we treat the pair tunneling and cotunneling on an equal footing. We propose an experimental setup to enhance the visibility of pair tunneling, which has no Franck-Condon suppression. We also discuss the shot noise characteristics.