Temperature and magnetic field dependence of a Kondo system in the weak coupling regime

TL;DR

This study demonstrates that the Kondo effect in a weakly coupled organic radical on gold can be accurately described by perturbation theory, emphasizing the importance of temperature and magnetic field dependence for understanding Kondo physics.

Contribution

It provides a quantitative comparison between experimental observations and Kondo theory for a weakly coupled spin-1/2 system, confirming the theory's applicability.

Findings

Zero-bias anomaly matches perturbation theory predictions

Kondo resonance depends on temperature and magnetic field

Identification of a spin 1/2 Kondo system

Abstract

The Kondo effect arises due to the interaction between a localized spin and the electrons of a surrounding host. Studies of individual magnetic impurities by scanning tunneling spectroscopy have renewed interest in Kondo physics; however, a quantitative comparison with theoretical predictions remained challenging. Here we show that the zero-bias anomaly detected on an organic radical weakly coupled to a Au (111) surface can be described with astonishing agreement by perturbation theory as originally developed by Kondo 60 years ago. Our results demonstrate that Kondo physics can only be fully conceived by studying both temperature and magnetic field dependence of the resonance. The identification of a spin 1/2 Kondo system is of relevance not only as a benchmark for predictions for Kondo physics but also for correlated electron materials in general.