Interplay between Hund's rule and Kondo effect in a quantum dot
Abstract
The interaction between localized spins on a quantum dot and free electrons in the reservoirs forms a many-particle entangled system giving rise to the Kondo effect. Here, we investigate electron transport in the third shell of a gate-defined GaAs quantum dot. The addition energy shows a maximum at half-filling of the shell which can be described analytically with Hund's rule exchange interaction. For 7 to 11 electrons occupying the quantum dot Zero-bias anomalies characteristic for the Kondo effect are observed, but with unexpected widths. Here the quantum dot has to be described as a multi-orbital Kondo impurity with Hund's interaction. In this way this quantum dot can be seen as a model system for a Hund's coupled mixed-valence quantum impurity as appearing in Hund's metals where local ferromagnetic interactions between orbitals lead to the emergence of complex electronic states.
Cite
@article{arxiv.2505.21675,
title = {Interplay between Hund's rule and Kondo effect in a quantum dot},
author = {Olfa Dani and Johannes C. Bayer and Timo Wagner and Gertrud Zwicknagl and Rolf J. Haug},
journal= {arXiv preprint arXiv:2505.21675},
year = {2025}
}
Comments
11 pages, 9 figures