Effect of interface disorder on quantum well excitons and microcavity polaritons

Abstract

The theory of the linear optical response of excitons in quantum wells and polaritons inplanar semiconductor microcavities is reviewed, in the light of the existing experiments.For quantum well excitons, it is shown that disorder mainly affects the excitoncentre-of-mass motion and is modelled by an effective Schrödinger equation in twodimensions. For polaritons, a unified model accounting for quantum well roughness andfluctuations of the microcavity thickness is developed. Numerical results confirm thatpolaritons are mostly affected by disorder acting on the photon component, thusconfirming existing studies on the influence of exciton disorder. The polaritonlocalization length is estimated to be in the few-micrometres range, dependingon the amplitude of disorder, in agreement with recent experimental findings.