Nonequilibrium resonant spectroscopy of molecular vibrons

TL;DR

This paper presents a nonequilibrium Green function approach to study how molecular vibrations influence quantum transport in single-molecule devices, enabling the identification of molecular orbital energies and vibrational spectra.

Contribution

The authors develop a theoretical framework for nonequilibrium resonant spectroscopy in molecular transport, accounting for intermediate electron-vibron coupling and lead interactions.

Findings

Resonant spectroscopy can determine molecular orbital energies.

Vibrational spectra significantly affect transport properties.

The theory aligns with scanning tunneling spectroscopy experiments.

Abstract

Quantum transport through single molecules is essentially affected by molecular vibrations. We investigate the behavior of the prototype single-level model with intermediate electron-vibron coupling and arbitrary coupling to the leads. We have developed a theory which allows to explore this regime via the nonequilibrium Green function formalism. We show that the nonequilibrium resonant spectroscopy is able to determine the energies of molecular orbitals and the spectrum of molecular vibrations. Our results are relevant to scanning tunneling spectroscopy experiments, and demonstrate the importance of the systematic and self-consistent investigation of the effects of the vibronic dynamics onto the transport through single molecules.