Kondo effect in optics of quantum dots

TL;DR

This paper explores how the Kondo effect influences the optical properties of quantum dots, revealing new midgap excitonic states caused by Kondo shake-up processes, even in cases where the ground state lacks the effect.

Contribution

It extends the Anderson impurity model to include both particle and hole charge excitations, uncovering novel excitonic states in quantum dots with even electron numbers.

Findings

Midgap excitonic states emerge due to Kondo shake-up processes.

Kondo effect influences optical spectra even without ground state Kondo effect.

Model relevance to rare earth ions on metallic surfaces.

Abstract

Anderson impurity model for semiconductor quantum dot is extended to take into account both particle and hole branches of charge excitations. It is shown that in dots with even number of electrons where the Kondo effect is absent in the ground state, novel midgap excitonic states emerge in the energy spectrum due to Kondo-type shake-up processes. The relevance of the model to rare earth ions adsorbed on metallic surfaces is discussed.