Second-order polaron resonances in self assembled quantum dots

TL;DR

This paper investigates the optical properties of InAs/GaAs quantum dots near second-order electron-phonon resonances, highlighting the importance of 3-phonon states and the impact of quantum dot geometry on resonance features.

Contribution

It introduces a minimal model incorporating 3-phonon states to accurately describe second-order polaron resonances in quantum dots.

Findings

The absorption spectra show significant effects of 3-phonon states.

Quantum dot height-to-width ratio influences resonance width and position.

The model accurately predicts the optical behavior near second-order resonances.

Abstract

We theoretically study the optical properties of an InAs/GaAs quantum dot (QD) near the area of the second-order resonance between an electron confined in the QD and two longitudinal optical phonons. We present the absorption spectra of an inhomogeneously broadened QD ensemble and show that the minimal model needed for an accurate description of such a system needs to account for 3-phonon states. We study also the influence of the QD height to width ratio on the optical properties of the polaron system. The dependence of the width of the resonance and the position of the second-order resonant feature on the height to width ratio is presented.