Ricerc@Sapienza

Emerging quantum technologies demands for the development of near-ideal sources of non-classical light [1]. For real-life applications, these sources should fulfill a series of requirements such as true on-demand generation of single and entangled photons, high brightness, and high indistinguishability of emitted photons. Among the many sources available to date, quantum dots are gaining attention as they can fulfill all the requirement of the wish list of single photon sources and, moreover, can generate highly entangled photon pairs through the two-photon cascade from the biexciton state to the ground state.
In this project we present a novel approach to retrieve a cascade of four quantum correlated photons from a single GaAs quantum dot. To achieve this objective a great effort will be devoted to understand and exploit the electronic band structure of these quantum nanostructures. This project will combine well-established spectroscopic techniques (such as photoluminescence and photoluminescence excitation) with photon correlation spectroscopy. The expected results of this experiment would shine light on the multiparticle energy structure of quantum dots and moreover, would provide an interesting tool to implement more complicated quantum protocols involving a higher number of correlated photons. The project will be part of the research line of the Nanophotonics group of the Physics Department of Sapienza University of Rome. The research will be performed thanks to the facilities already present in the laboratory and by implementing a part of the experimental setup with a new laser pulse tailoring device.
[1] Senellart, P., et al. Nature Nanotechnology 12, 1026¿1039 (2017).