One, Two, Many Modes: Developent & Application of High-dimensional Systems for Quantum Information Science (Dr. R. Kruse)

In communication, computation and metrology, this aim necessitates the implementation of large Hilbert spaces. Therefore in quantum optics, the challenge is to push existing technology and develop compact architectures that implement large quantum networks with many photons for large Hilbert spaces.

In this talk, we focus on three recent results in this area. First, we discuss a novel type of photon pair source that utilises, in addition to the intrinsic non-linearity of the material, the evanescent field coupling between two waveguides to specifically engineer the spatial properties of the generated photons. Second, we investigate the scalability of an established quasi-photon number resolving measurement technique. While generally considered intrinsically scalable, we consider realistic experimental parameters for time-multiplexed photon number measurements and pin down the limitations in the scalability. Finally, we combine these two ingredients and probe the generated nonclassicality of our source with time-multiplexed photon-number measurements under experimentally simulated atmospheric conditions.