Quenching of phonon-induced processes in quantum dots due to electron-hole asymmetries

TL;DR

This paper investigates how electron-hole asymmetries in quantum dots influence phonon scattering, demonstrating that phonon-induced processes can be significantly suppressed through quantum dot shape engineering, with implications for quantum optics.

Contribution

It introduces a detailed model showing how electron-hole asymmetries affect phonon scattering and proposes methods to quench this scattering in quantum dot systems.

Findings

Phonon scattering can be strongly quenched by tailoring quantum dot shape.

Electron-hole asymmetries significantly impact phonon-induced processes.

The model predicts conditions for effective phonon quenching in cavity QED systems.

Abstract

Differences in the confinement of electrons and holes in quantum dots are shown to profoundly impact the magnitude of scattering with acoustic phonons in materials where crystal deformation shifts the conduction and valence band in the same direction. Using an extensive model that includes the non-Markovian nature of the phonon reservoir, we show how the effect may be addressed by photoluminescence excitation spectroscopy of a single quantum dot. We also investigate the implications for cavity QED, i.e. a coupled quantum dot-cavity system, and demonstrate that the phonon scattering may be strongly quenched. The quenching is explained by a balancing between the deformation potential interaction strengths and the carrier confinement and depends on the quantum dot shape. Numerical examples suggest a route towards engineering the phonon scattering.