Dephasing of excitons in CdTe self-organized quantum dots

Four-wave mixing (FWM) technique is used to study the phonon induced dephasing of the excitons in CdTe self-assembled quantum dots. The FWM signals show two different decay structures with fast and slow decay components, indicating a non-Lorentzian line-shape with a zero-phonon line and a broadband from exciton–acoustic phonon interaction in the spectral region. The dephasing of the zero-phonon line and the sideband components both show non-linear characteristics with respect to temperature. The experimental data are reproduced well by a theoretical model taking into account the carrier–acoustic phonon coupling.