ISOQC: Integrated Superconducting Optoelectronics for Quantum Communication

The aim of this project is the integration and application of high-efficiency superconducting detectors on nonlinear lithium niobate waveguides. This will enable to development of new tools in quantum optical communication technology. The main challenge is to maintain the advantages of the high nonlinearity of lithium niobate at the cryogenic temperatures required to operate the superconducting detectors, as well as ensure that the processing steps for each technology are mutually compatible. We have already made the first steps towards these goals in isolation; the new and exciting aspect of this project is to combine these functionalities on a single device, in order to realise the full potential of this technology. To do so, we combine the weald-leading lithium niobate waveguide fabrication at Paderborn University with the superconducting detector technology from the National Institute for Standards and Technology (NIST) in Boulder, Colorado. We plan to build five tailor-made modules to demonstrate the versatility of the the integrated superconducting optoelectronic platform. This comprises optimising the material properties of lithium niobioate waveguides with the thin-film superconductors required for the detectors. Each of these components will be designed such that it may be included as part of a wider quantum communication system, which can interconnect with other devices based on other platforms, for example single photon sources from single emitters. This modular approach, whereby the optimisation can be carried out on a component-by-component basis, is essential for the proliferation of quantum technology. The long-term vision is that this approach adds significant value and enables a broad functionality for quantum communication technology.