Pair Tunneling and shot noise through a single molecule in a strong   electron-phonon coupling
  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 non-equilibrium 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. 
Myung-Joong Hwang, Mahn-Soo Choi, Rosa Lopez