Effects of non-adiabaticity in optical spectra ofsemiconductor quantum dots

摘要

We show that in many cases an adequate description of optical spectra ofsemiconductor quantum dots requires a treatment beyond the commonly used adiabaticapproximation. We have developed a theory of phonon-assisted optical transitions insemiconductor quantum dots, which takes into account non-adiabaticity of the exciton-phononsystem. Effects of non-adiabaticity lead to a mixing of different exciton and phonon statesthat provides a key to the understanding of surprisingly high intensities of phonon satellitesobserved in photoluminescence spectra of quantum dots. A breakdown of the adiabaticapproximation gives an explanation also for discrepancies between the serial law, observedin multi-phonon optical spectra of some quantum dots, and the Franck-Condon progression,prescribed by the adiabatic approach.