Scalable Continuous Variable Cluster State Quantum Technologies

Continuous variable (CV) quantum technologies have in recent years made significant impact on the fields of quantum communication, sensing, and computing, as signified by the detection of gravitational waves and demonstration of quantum advantage via Gaussian boson sampling. Moreover, the recent generation and manipulation of CV cluster states, comprising thousands of entangled modes, have direct implications for future developments of scalable CV quantum computing and networking systems. In CLUSTEC, we will pursue an interdisciplinary approach to unfold the full potential of CV cluster state technology by making conceptual and technical breakthroughs along three different directions. First, we will develop two complementary optical platforms for scalable generation of massive CV cluster states of different entanglement topologies and generation of hardware efficient error-correcting codes. The two systems will be based on a well-established low-loss fiber platform and the emerging, highly promising integrated photonics platform of thin-film Lithium Niobate. Second, we will develop and test radically new measurement-induced CV quantum computational and networking protocols and algorithms with certified quantum advantage and real-life applications. Third, we will explore and develop, theoretically and experimentally, novel quantum error-correcting CV protocols and technologies that facilitate the realization of practical fault-tolerant quantum technologies for quantum computing, communication and sensing with true scalability potential. With these activities, CLUSTEC will create a new path towards scalable quantum technologies and accelerate the development of practical quantum technologies with potentially radical impact on European society and economy. The results will pave the way for industrial uptake and exploitation in the near and long term, and in turn support the development of European leadership and autonomy in emerging strategic technologies.