Vibrational sidebands and dissipative tunneling in molecular transistors

Transport through molecular devices with strong coupling to a single vibrational mode is considered in the case where the vibration is damped by coupling to the environment. We focus on the weak tunneling limit, for which a rate equation approach is valid. The role of the environment can be characterized by a frictional damping term $\mathcal{S}(\ensuremath{\omega})$ and a corresponding frequency shift. We consider a molecule that is attached to a substrate, leading to a frequency-dependent fric