Franck-Condon blockade and giant Fano factors in transport through single molecules

Abstract

We show that Franck-Condon physics leads to a significant current suppression at low bias voltages (termed Franck-Condon blockade) in transport through single molecules with strong coupling between electronic and vibrational degrees of freedom. We find that transport in this regime is characterized by remarkably large Fano factors ($10^2$--$10^3$), which arise due to avalanche-like transport of electrons. Avalanches occur in a self-similar manner over a wide range of time scales, as reflected in power-law dependences of the current noise on frequency and vibrational relaxation rate.

4+ pages, 4 figures; minor changes, version accepted for publication in Phys. Rev. Lett

References in corpus (2)

• Electrical generation and absorption of phonons in carbon nanotubes
• Shot Noise of a Quantum Shuttle

Cited by in corpus (4)

• Tunneling in suspended carbon nanotubes assisted by longitudinal phonons
• Current-induced nonequilibrium vibrations in single-molecule devices
• Full counting statistics of strongly non-Ohmic transport through single molecules
• Effects of charge-dependent vibrational frequencies and anharmonicities in transport through molecules