Linear optical response of current-carrying molecular junction: A NEGF-TDDFT approach

TL;DR

This paper introduces a NEGF-TDDFT method to calculate the linear optical response of molecular junctions under current flow, bridging NEGF and TDDFT formalisms for nonequilibrium systems.

Contribution

It develops a novel theoretical framework combining NEGF and TDDFT to analyze optical properties of current-carrying molecular junctions.

Findings

Derived expressions for optical response within NEGF-TDDFT.

Reproduced known TDDFT results for isolated molecules.

Established relationships between NEGF and TDDFT approaches.

Abstract

We propose a scheme for calculation of linear optical response of current-carrying molecular junctions for the case when electronic tunneling through the junction is much faster than characteristic time of external laser field. We discuss relationships between nonequilibrium Green function (NEGF) and time-dependent density functional theory (TDDFT) approaches, and derive expressions for optical response and linear polarizability within NEGF-TDDFT scheme. Corresponding results for isolated molecule, derived within TDDFT approach previously, are reproduced when coupling to contacts is neglected.