Electron Transport through a Molecular Conductor with Center-of-Mass Motion

TL;DR

This paper investigates how a vibrating molecular conductor's electron transport properties are affected by interference effects, revealing a conductance dip at symmetry points due to destructive interference between electronic and phonon-assisted tunneling channels.

Contribution

It introduces a numerical analysis of conductance in a vibrating molecular conductor considering both Hubbard interactions and noninteracting electrons, highlighting interference effects.

Findings

Conductance dip at electron-hole symmetry point due to interference.

Destructive interference between electronic and phonon-assisted tunneling channels.

Fano-like interference persists with active vibrational modes.

Abstract

The linear conductance of a molecular conductor oscillating between two metallic leads is investigated numerically both for Hubbard interacting and noninteracting electrons. The molecule-leads tunneling barriers depend on the molecule displacement from its equilibrium position. The results present an interesting interference which leads to a conductance dip at the electron-hole symmetry point, that could be experimentally observable. It is shown that this dip is caused by the destructive interference between the purely electronic and phonon-assisted tunneling channels, which are found to carry opposite phases. When an internal vibrational mode is also active, the electron-hole symmetry is broken but a Fano-like interference is still observed.