Polarization Dependent Correlations of Single Photons from CdTe/ZnTe Quantum Dots

Temporal and polarization correlations between single photons emitted from different excitonic states confined in the same CdTe/ZnTe quantum dot (QD) were measured. Experiment was carried out at low temperature (T = 1.7 K) with nonresonant excitation and in an external magnetic field ranging from 0 to 5 T. The collinear polarization correlation of photons emitted in biexciton (XX) - exciton (X) cascade in the anisotropic QD is converted in magnetic field to counter-circular polarization correlation. Measurements of charged exciton - neutral exciton crosscorelations revealed that spin orientation of a single carrier left in the dot after charged exciton recombination is preserved in magnetic field over the laser pulse repetition period of more than ten nanoseconds. The spin memory is not destroyed by capture of a next carrier.