Kondo-excitons and Auger processes in self-assembled quantum dots

TL;DR

This paper theoretically investigates novel excitonic phenomena in self-assembled quantum dots interacting with a 2D electron gas, revealing voltage-dependent optical lines, Kondo effects, and Auger processes, some of which align with recent experimental observations.

Contribution

It introduces a theoretical framework for understanding Kondo-excitons and Auger processes in quantum dots, highlighting their voltage dependence and magnetic field behavior.

Findings

Optical lines are voltage-dependent in the presence of a Fermi sea.

Line width relates to Kondo temperature when electron spin is nonzero.

Anticrossings occur due to Auger-like processes in magnetic fields.

Abstract

We describe theoretically novel excitons in self-assembled quantum dots interacting with a two-dimensional electron gas in the wetting layer. In the presence of the Fermi sea, the optical lines become strongly voltage-dependent. If the electron spin is nonzero, the width of optical lines is given by k_BT_K, where T_K is Kondo temperature. If the spin is zero, the exciton couples with the continuum due to Auger-like processes. This leads to anticrossings in a magnetic field. Some of the described phenomena are observed in recent experiments.