Polaron relaxation in self-assembled quantum dots: Breakdown of the semi-classical model

TL;DR

This paper investigates the relaxation mechanisms of polarons in self-assembled quantum dots, demonstrating the limitations of semi-classical models and emphasizing the importance of anharmonic phonon interactions for accurate lifetime predictions.

Contribution

It provides a detailed quantum-mechanical calculation of polaron lifetimes considering anharmonic phonon couplings, revealing the breakdown of semi-classical approaches.

Findings

Polaron lifetime depends strongly on energy and anharmonic decay channels.

Semi-classical models are insufficient for accurate polaron relaxation description.

Results align with experimental measurements of polaron decay in InAs/GaAs quantum dots.

Abstract

We calculate the lifetime of conduction band excited states in self-assembled quantum dots by taking into account LO-phonon-electron interaction and various anharmonic phonon couplings. We show that polaron relaxation cannot be accurately described by a semi-classical model. The contributions of different anharmonic decay channels are shown to depend strongly on the polaron energy. We calculate the energy dependence of polaron lifetime and compare our results to available experimental measurements of polaron decay time in InAs/GaAs quantum dots.