Influence of inter-dot coupling on spin polarization of carriers in double quantum dots

Abstract

We have performed magneto-photoluminescence (PL) experiments on a self-assembled coupled double quantum dot (QD) system consisting of adjacent CdSe and CdZnSe QD layers. We have observed well-separated two PL peaks in such a double layer QD system, corresponding to the CdSe and the CdZnSe QDs. The PL signal was studied using circularly polarized detection. The intensities of the two PL peaks exhibited significant differences for the two circular polarizations when a magnetic field applied, in contrast to the behaviour shown by single layer CdSe or CdZnSe QD systems, which show nearly identical polarization dependence on the field. The observed behaviour can be interpreted in terms of interaction between carriers localized in pairs of QDs that are electronically coupled.