A quantum mechanical flux correlation approach to steady-state transport rates in molecular junctions

A time-dependent approach for the calculation of steady-state currents through molecular junctions is presented. Using the close analogy between electronic currents and thermal reactive scattering rates, algorithms and methodologies originally developed for calculations of thermal reaction rates are utilized for electronic transport calculations. Resonant transport is considered in detail, in view of the dominant contribution of resonance states to the current in molecular junctions. The problem of long-time delays due to population of long-lived resonances is a challenge for most time-dependent calculation of steady-state currents, involving an infinite time-limit. A solution to this problem is presented by reformulating a flux-averaging method for the molecular junction scenario. The new formulation is implemented for commonly used simple tight binding models of molecular junctions, demonstrating its numerical advantages.