Electronic transport through a biphenyl system as a function of torsion angle with a complex absorbing potential to model the self-energy in a scattering approach

Abstract

In this work, we present a self-energy model based on the complex absorbing potential (CAP) method to calculate the transmission function through an extended molecule using scattering theory. Once the CAP mimics an infinite environment at the ends of a finite system, it can be used as a model for self-energy with a low computational cost. Moreover, the matrixes required for the transport calculation can be obtained from an ab initio calculation of some extended molecules in a single step using an adjustable model, thus taking into account changes in the electronic structure of the system. This approach was applied to study electron transport across a biphenyl molecular system for different torsion angles under an external applied electric field. The results obtained are in good agreement with the available theoretical and experimental results in the literature and provide an efficient approach, with a low computational cost method, for the interpretation of electrical transport at the molecular level.