---
abstract: 'In a multi-electron atom, an excited electron can decay by emitting a photon. Typically, the leftover electrons are in their ground state. In a radiative Auger process, the leftover electrons are in an excited state and a red-shifted photon is created [@Aberg1969; @Aberg1971; @Bloch1935b]. In a quantum dot, radiative Auger is predicted for charged excitons [@Michler2003]. For a singly-charged trion, a photon is created on electron-hole recombination, leaving behind a single electron. Radiative Auger determines the quantisation energies of this single electron, information which is otherwise difficult to acquire. For this reason, radiative Auger is a powerful tool. However, radiative Auger has not been observed on single quantum dots. Here, we report radiative Auger on trions in single quantum dots. There are sharp red-shifted emission lines with intensities as high as 1% of the main emission enabling the single-electron quantisation energies to be measured with high precision. Going beyond the original proposals, we show how quantum optics – an analysis of the photon correlations – gives access to the single-electron dynamics, notably relaxation and tunneling. All these properties of radiative Auger can be exploited on other semiconductor nanostructures and colour centres.'
author:
- 'Matthias C. Löbl'
- Clemens 