Kondo effect by controlled cleavage of a single molecule contact

TL;DR

This study demonstrates how controlled mechanical manipulation of a single-molecule contact can induce the Kondo effect, revealing new insights into molecular-scale quantum transport and enabling advanced experimental and theoretical investigations.

Contribution

It introduces a novel method to induce and study the Kondo effect in single-molecule junctions through precise contact control, bridging experimental techniques and theoretical modeling.

Findings

Kondo resonance observed during controlled molecule-metal contact retraction

Numerical simulations confirm the generic nature of the Kondo behavior in such systems

New approach for single-molecule experiments with atomic-scale contact control

Abstract

Conductance measurements of a molecular wire, contacted between an epitaxial molecule-metal bond and the tip of a scanning tunneling microscope, are reported. Controlled retraction of the tip gradually de-hybridizes the molecule from the metal substrate. This tunes the wire into the Kondo regime in which the renormalized molecular transport orbital serves as spin impurity at half filling and the Kondo resonance opens up an additional transport channel. Numerical renormalization group simulations suggest this type of behavior to be generic for a common class of metal molecule bonds. The results demonstrate a new approach to single-molecule experiments with atomic-scale contact control and prepare the way for the ab initio simulation of many-body transport through single-molecule junctions.