Kondo resonances and anomalous gate dependence of electronic conduction in single-molecule transistors

TL;DR

This paper reports the observation of high-temperature Kondo resonances in single-molecule transistors, revealing unusual gate dependence that challenges existing models and suggesting complex electronic interactions.

Contribution

It demonstrates Kondo effects in molecular transistors with high Kondo temperatures and explores their unconventional gate dependence, advancing understanding of molecular electronic systems.

Findings

Kondo temperatures >50 K in molecular transistors

Unusual gate dependence of Kondo temperature

Inconsistency with simple single-dot models

Abstract

We report Kondo resonances in the conduction of single-molecule transistors based on transition metal coordination complexes. We find Kondo temperatures in excess of 50 K, comparable to those in purely metallic systems. The observed gate dependence of the Kondo temperature is inconsistent with observations in semiconductor quantum dots and a simple single-dot-level model. We discuss possible explanations of this effect, in light of electronic structure calculations.