| AVS 63rd International Symposium & Exhibition | |
| Magnetic Interfaces and Nanostructures | Tuesday Sessions |
| Session MI-TuA |
| Session: | Magnetic Phenomena in Organic Systems |
| Presenter: | Peter Wahl, University of St Andrews, UK |
| Correspondent: | Click to Email |
The Kondo effect is one of the most intensely investigated many-particle problems in solid-state physics. While it was discovered originally in dilute magnetic alloys, the same physics emerges in seemingly unrelated contexts, such as the zero-bias anomalies observed in quantum dots or the dynamical behavior close to a Mott transition. The simplicity of the underlying hamiltonian – a single spin coupled by an exchange interaction J to a bath of conduction electrons – contrasts the complex physics emerging from it as well as the challenges met in theoretical calculations. Apart from being a drosophila for electronic correlation effects, the single impurity Kondo effect is an elementary building block for model lattice systems relevant for strongly correlated electron materials such as high temperature superconductors.
Studies of transition metal atoms on metal surfaces by low temperature scanning tunneling microscopy and spectroscopy have renewed interest in the Kondo problem by providing access to local properties; however a quantitative comparison with theoretical predictions remained challenging.
Here I present a study of an organic radical with a single spin ½ on Au(111) [1]. Tunneling spectra reveal a zero bias anomaly as would be expected for a Kondo system, yet comparison of the temperature and magnetic field dependence of the zero bias anomaly with predictions of the Kondo effect in the strong coupling regime are in apparent disagreement. Detailed comparison with theoretical models reveals quantitative agreement with the original Kondo model in the weak coupling regime.
1. Y. Zhang et al., Nat. Commun. 4, 2110 (2013).