Executive Summary : | Low decoherence along with matured optical technologies have established photonic systems as an exciting candidate for the generation of a large-scale quantum network, a key building block for future quantum technologies. Another exciting feature of photonic platforms for quantum information technologies is the possibility to exploit various optical degrees of freedom (polarization, spatial, temporal, time bins, spectral) for information encoding. Although the current technology permits the generation of quantum light in several degrees of freedom, most of the existing schemes to construct optical quantum networks utilize only one at a time. Moreover, the current techniques to design and characterize optical quantum networks follow either a discrete-variable (DV) approach that exploits photon nature or a continuous-variable (CV) approach utilizing the wave-like behavior of light. This action introduces an all-optical scheme capable of implementing one-, two-, and even high-dimensional quantum networks that employ multiple degrees of freedom of quantum light as well as quantum feedback. Additionally, the network will facilitate both DV and CV approaches, thus opening up novel hybrid quantum information protocols. We will implement a time-multiplexed optical network with a feedback loop for time-bin encoding and combine it with a type-II parametric down-conversion (PDC) process in multiple temporal/spectral modes, thus exploiting polarization, temporal/spectral, and time-bin modes of light. Moreover, this scheme can easily be adapted to generate both DV and CV quantum networks since the PDC process introduces quantum correlations in photon numbers as well as in field quadratures. This novel photonic platform in conjunction with DV/CV quantum light not only triggers the search for finding a unified detection and characterization technique suitable for both cases but also paves the path for the realization of practical quantum simulation and computation in the longer run. |