Thermopower for a molecule with vibrational degrees of freedom

Abstract

We propose a simple model to study resonant tunneling through an organic molecule between to conducting leads, taking into account the vibrational modes of the molecule. We solve the model approximately analytically in the weak coupling limit and give explicit expressions for the thermopower and Seebeck coefficient. The behavior of these two quantities is studied as function of model parameters and temperature. For a certain regime of parameters a rather peculiar variation of the thermopower and Seebeck coefficient is observed. Although the model is very simple, we expect it to give some nontrivial insight into thermal transport properties through nan-devices. Furthermore, because we can provide an analytical solution, it may eventually serve as benchmark for more advanced analytical or computational methods.