Role of Nearly-Degenerate Vibrational Modes in Electron Transport through a Molecular Junction

TL;DR

This paper introduces a method to simplify the analysis of electron transport in molecular junctions by reducing nearly-degenerate vibrational modes to an effective single mode, significantly decreasing computational effort.

Contribution

The authors develop a master equation approach that maps nearly-degenerate phonon modes into an effective single mode, enabling efficient and accurate conductance spectrum calculations.

Findings

Effective single mode accurately reproduces conductance spectra.

Reduction in computational time by orders of magnitude.

Applicable to complex molecular junctions like OPV-5.

Abstract

We consider an open molecular junction in which electrons are coupled to multi-mode phonons. Using a master equation approach for equilibrated phonons, we show that nearly-degenerate phonon modes can be mapped into an effective single mode, which can result in a noticeable reduction of computational costs. As an illustration, we apply our theory to the OPV-5 molecule and show that we can obtain the consistent conductance spectra while reducing the computational time by orders of magnitude