Exciton and multi-exciton structures in GaAs quantum dots studied by single-photon correlation spectroscopy

Single-photon emitters and detectors are key devices for realizing secure communications by single-photon-based cryptography and single-photon-based quantum computing. For the establishment of these technologies, we need to understand the electronic structures of single and multiple excitons. Therefore, we have studied their emissions via the micro-photoluminescence (μ-PL) spectra of strain-free GaAs/AlGaAs single quantum dots, using excitation power dependence, time-resolved, and single-photon correlation measurements. Under pulsed excitation, we observed clear photon antibunching and bunching by auto- and cross-correlation measurements. From these results, we found that the emission peaks observed in the μ-PL spectra originated from exciton, charged exciton, and biexciton states.