Vibration-assisted electron tunneling in C_{140} single-molecule transistors

TL;DR

This paper investigates how vibrational modes in a C_{140} molecule influence electron tunneling in single-molecule transistors, revealing mode-specific coupling effects and comparing experimental results with theoretical models.

Contribution

It demonstrates vibration-assisted tunneling in C_{140} molecules and explains mode-specific coupling using molecular modeling, advancing understanding of electron-vibration interactions.

Findings

Vibration-assisted tunneling occurs at the C_{140} stretching mode.

The mode couples more strongly to tunneling than other internal modes.

Experimental tunneling rates align with Franck-Condon model predictions.

Abstract

We measure electron tunneling in single-molecule transistors made from C_{140}, a molecule with a mass-spring-mass geometry chosen as a model system to study electron-vibration coupling. We observe vibration-assisted tunneling at an energy corresponding to the stretching mode of C_{140}. Molecular modeling provides explanations for why this mode couples more strongly to electron tunneling than the other internal modes of the molecule. We make comparisons between the observed tunneling rates and those expected from the Franck-Condon model.