Spatial correlations and Raman scattering interferences in self-assembled quantum dot multilayers

Raman scattering is shown to provide an effective means to measure spatial correlations in self-assembled quantum dot multilayers. Raman scattering interferences occur when an acoustic phonon interacts with an ensemble of localized electronic states. The interference contrast depends on their spatial correlations. Vertical correlations in self-assembled Ge/Si quantum dot multilayers are deduced from the interference contrast and successfully compared with those measured by transmission electron microscopy.