Correlated photon emission from a single II–VI quantum dot

We report correlation and cross-correlation measurements of photons emitted under continuous wave excitation by a single II–VI quantum dot (QD) grown by molecular-beam epitaxy. A standard technique of microphotoluminescence combined with an ultrafast photon correlation setup allowed us to see an antibunching effect on photons emitted by excitons recombining in a single $\mathrm{CdTe}∕\mathrm{ZnTe}$ QD, as well as cross correlation within the biexciton $\left(X_2\right)$ -exciton $\left(X\right)$ radiative cascade from the same dot. Fast microchannel plate photomultipliers and a time-correlated single photon module gave us an overall temporal resolution of $140\mathrm{ps}$ better than the typical exciton lifetime in II–VI QDs of about $250\mathrm{ps}$ .