# Phonon-assisted dark exciton preparation in a quantum dot

## TL;DR

This paper investigates how phonons influence the optical preparation of dark excitons in quantum dots, showing that phonons can either be negligible or beneficial, thus enhancing the feasibility of using dark excitons in quantum technologies.

## Contribution

It provides a detailed analysis of phonon effects on two optical dark exciton preparation methods, revealing phonons can assist or not hinder the process, expanding practical applications.

## Key findings

- Phonons do not impede dark exciton preparation in certain conditions.
- Phonons can widen the parameter range for successful dark exciton preparation.
- Phonon-assisted methods improve the robustness of dark exciton state preparation.

## Abstract

In semiconductor quantum dots the coupling to the environment, i.e. to phonons, plays a crucial role for optical state preparation. We analyze the phonon impact on two methods for a direct optical preparation of the dark exciton, which is enabled by a tilted magnetic field: the excitation with a chirped laser pulse and the excitation with a detuned pulse. Our study reveals that for both methods phonons either do not impede the proposed mechanism or are even useful by widening the parameter range where a dark state preparation is possible due to phonon-assisted dark exciton preparation. In view of the positive impact of phonons on the optical preparation the use of dark excitons in quantum dots becomes even more attractive.