Photonic quantum technologies: from integrated quantum devices to designing large complex system
Quantum technologies promise a change of paradigm for many fields of application. However, their implementation often requires advanced setups of high complexity, because scaling photonic quantum systems many controllable modes and input states with many photons.
Here we review different approaches for the experimental implementation of future multi-dimensional photonic quantum systems, including Gaussian Boson sampling and time-frequency multiplexing. Our systems comprise non-linear integrated quantum devices, source engineering and pulsed temporal modes as well as time-multiplexed architectures.
Non-linear integrated quantum devices with multiple channels and tailored functionalities are required for implementation of suitable quantum circuits, which include high-performance quantum sources and fast electro-optic modulations on compact monolithic structures. We investigate the use of thin-film lithium niobate circuits together with new concepts to establish a toolbox of integrated devices tailored for quantum applications.
For the engineering of future-oriented quantum light structures, pulsed photon temporal modes are an attractive platform for advanced quantum information encoding. They are defined as field-orthogonal superposition states and constitute a high-dimensional quantum system, which is naturally present in current nonlinear quantum light sources. Here, the control of these temporal modes is key for the realization efficient quantum network architectures based on quantum inference.
Time-multiplexed quantum systems allow for the efficient implementation of scalable and configurable networks with many modes and dynamic control of the underlying graph structures. This enables, e.g. feed-forward operations and source multiplexing for realizing efficient entanglement generation as well as the realization of flexible advanced quantum circuits for future quantum computation and simulation.