Effect of interface disorder on quantum well excitons and microcavity polaritons

TL;DR

This paper reviews how interface disorder impacts excitons in quantum wells and polaritons in microcavities, showing disorder mainly affects photon components and influences localization lengths, aligning with experimental data.

Contribution

It introduces a unified model for disorder effects on polaritons considering both quantum well roughness and microcavity fluctuations, with numerical validation.

Findings

Disorder affects exciton center-of-mass motion in quantum wells.

Polaritons are mainly influenced by photon component disorder.

Localization length of polaritons is a few micrometers, consistent with experiments.

Abstract

The theory of the linear optical response of excitons in quantum wells and polaritons in planar semiconductor microcavities is reviewed, in the light of the existing experiments. For quantum well excitons, it is shown that disorder mainly affects the exciton center-of-mass motion and is modeled by an effective Schroedinger equation in two dimensions. For polaritons, a unified model accounting for quantum well roughness and fluctuations of the microcavity thickness is developed. Numerical results confirm that polaritons are mostly affected by disorder acting on the photon component, thus confirming existing studies on the influence of exciton disorder. The polariton localization length is estimated to be in the few-micrometer range, depending on the amplitude of disorder, in agreement with recent experimental findings.