Decoherence in quantum dots due to real and virtual transitions: a non-perturbative calculation

TL;DR

This paper presents a non-perturbative theoretical analysis of acoustic phonon-induced decoherence in quantum dots, focusing on real and virtual transitions affecting optical transition dephasing.

Contribution

It introduces an analytic expression for phonon-induced broadening considering up to two phonon processes, applied specifically to intersublevel transitions in quantum dots.

Findings

Derived an analytic formula for phonon broadening

Quantified the impact of real and virtual transitions on decoherence

Applied theory to self-assembled quantum dots

Abstract

We investigate theoretically acoustic phonon induced decoherence in quantum dots. We calculate the dephasing of fundamental (interband or intraband) optical transitions due to real and virtual transitions with higher energy levels. Up to two acoustic phonon processes (absorption and/or emission) are taken into account simultaneously in a non-perturbative manner. An analytic expression of acoustic phonon induced broadening is given as a function of the electron-phonon matrix elements and is physically interpreted. The theory is applied to the dephasing of intersublevel transitions in self-assembled quantum dots.