Lifting the Franck-Condon blockade in driven quantum dots

Article

关键词: NANOTUBE MECHANICAL RESONATORS;    SINGLE-MOLECULE TRANSISTOR;    CARBON NANOTUBES;    ELECTRON-TRANSPORT;    OSCILLATOR;    SYSTEMS;   

DOI  :  10.1103/PhysRevB.94.205412

来源: SCIE

【 摘 要 】

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.

【 授权许可】

Free