Quantum inelastic conductance through molecular wires

TL;DR

This paper investigates how quantum coherence and electron-phonon interactions influence inelastic conductance in molecular wires, revealing that virtual polarons significantly enhance tunneling currents at sub-band-gap energies.

Contribution

It provides a non-perturbative quantum mechanical analysis of inelastic effects in molecular wire conductance, emphasizing the importance of full quantum coherence in polaron transport.

Findings

Inelastic conductance is dominated by virtual polarons at sub-band-gap energies.

Quantum coherence is essential for accurate modeling of polaron-mediated transport.

Tunneling current increases significantly due to inelastic effects involving electron-phonon coupling.

Abstract

We calculate non-perturbatively the inelastic effects on the conductance through a conjugated molecular wire-metal heterojunction, including realistic electron-phonon coupling. We show that at sub-band-gap energies the current is dominated by quantum coherent transport of virtual polarons through the molecule. In this regime, the tunneling current is strongly increased relative to the case of elastic scattering. It is essential to describe the full quantum coherence of the polaron formation and transport in order to obtain correct physics. Our results are generally applicable to one-dimensional atomic or molecular wires.