Manipulating Kondo Temperature via Single Molecule Switching

TL;DR

This study demonstrates that the Kondo temperature of a single molecule on a metal surface can be tuned by switching its conformation, affecting spin-electron interactions without chemical modifications.

Contribution

It introduces a method to control Kondo temperature through single molecule conformational switching using STM voltage pulses.

Findings

Switching conformations alters Kondo temperature from 130 K to 170 K.

Conformational change enhances spin-electron coupling.

Molecular conformation alone can tune Kondo effects.

Abstract

Two conformations of isolated single TBrPP-Co molecules on a Cu(111) surface are switched by applying +2.2 V voltage pulses from a scanning tunneling microscope tip at 4.6 K. The TBrPP-Co has a spin-active cobalt atom caged at its center and the interaction between the spin of this cobalt atom and free electrons from the Cu(111) substrate can cause a Kondo resonance. Tunneling spectroscopy data reveal that switching from the saddle to a planar molecular conformation enhances spin-electron coupling, which increases the associated Kondo temperature from 130 K to 170 K. This result demonstrates that the Kondo temperature can be manipulated just by changing molecular conformation without altering chemical composition of the molecule.