Polaronic effects induced by non-equilibrium vibrons in a single-molecule transistor

Abstract

Current-voltage characteristics of a single-electron transistor with a vibrating quantum dot were calculated assuming vibrons to be in a coherent (non-equilibrium) state. For a large amplitude of quantum dot oscillations we predict strong suppression of conductance and the lifting of polaronic blockade by bias voltage in the form of steps in I-V curves. The height of the steps differs from the prediction of the Franck-Condon theory (valid for equilibrated vibrons) and the current saturates at lower voltages than for the case, when vibrons are in equilibrium state.