Lifting the Franck-Condon blockade in driven quantum dots
arXiv:1608.01862 · doi:10.1103/PhysRevB.94.205412
Abstract
Electron-vibron coupling in quantum dots can lead to a strong suppression of the average current in the sequential tunneling regime. This effect is known as Franck-Condon blockade and can be traced back to an overlap integral between vibron states with different electron numbers which becomes exponentially small for large electron-vibron coupling strength. Here, we investigate the effect of a time-dependent drive on this phenomenon, in particular the effect of an oscillatory gate voltage acting on the electronic dot level. We employ two different approaches: perturbation theory based on nonequilibrium Keldysh Green's functions and a master equation in Born-Markov approximation. In both cases, we find that the drive can lift the blockade by exciting vibrons. As a consequence, the relative change in average current grows exponentially with the drive strength.
12 pages, 10 figures
References in corpus (14)
- A tunable carbon nanotube electromechanical oscillator
- Franck-Condon blockade and giant Fano factors in transport through single molecules
- Strong coupling between single-electron tunneling and nano-mechanical motion
- Carbon nanotubes as ultra-high quality factor mechanical resonators
- Franck-Condon blockade in suspended carbon nanotube quantum dots
- Theory of the Franck-Condon blockade regime
- Tunneling in suspended carbon nanotubes assisted by longitudinal phonons
- Tunneling through molecules and quantum dots: master-equation approaches
- Charge transfer statistics of a molecular quantum dot with a vibrational degree of freedom
- Charge transfer statistics of a molecular quantum dot with strong electron-phonon interaction
- High-frequency nanotube mechanical resonators
- Single electron transistor strongly coupled to vibrations: Counting Statistics and Fluctuation Theorem
- Long transient dynamics in the Anderson-Holstein model out of equilibrium
- Thermodynamics of the polaron master equation at finite bias