Time and Frequency Synchronized Intercity Quantum Communication (InterSync)

• Subject Area: Hardware Systems and Architectures for Information Technology and Artificial Intelligence, Quantum Engineering Systems ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 491585234

Quantum communication, which is the distribution of quanta among various locations, forms a cornerstone of modern quantum technologies. Based on the laws of quantum mechanics, a number of revolutionary applications have been envisioned, for example, physical secured communication, or quantum computing in distributed quantum networks, which may be used to tackle classes of problems that exceed the capacity of classical computers. After decades of exploration, however, it is still difficult to implement quantum communication under real-world conditions, due to optical loss, decoherence, fluctuations of the fiber length, or the refractive index which introduces additional noise in the timing signal.Here, we propose a testbed for real-world applications in quantum communication and networking, called Time and Frequency Synchronized Intercity Quantum Communication, in short InterSync. It consists of a fiber link between the Gottfried Wilhelm Leibniz Universität Hannover (LUH) and Germany’s central metrology institute, the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig. For high speed quantum communication, the connection features a precise timing system to synchronize quantum measurements among the two locations. InterSync’s testbed will be the first of its kind in Germany, which allows for a number of emerging quantum hardware, software, and protocols to be tested on a metrology-assisted long-distance fiber.InterSync will be set up in the highly active and collaborative research environment in Lower Saxony with two related excellence clusters (PhoenixD and QuantumFrontiers) and the Quantum Valley Lower Saxony (QVLS) as a large scale initiative for quantum computing in its close vicinity. Utilizing the capabilities of PTB in metrology and especially time dissemination, InterSync will provide a unique infrastructure for advanced quantum communication and technologies with an expected user base throughout Germany and Europe and even world-wide.The quantum infrastructure system of InterSync links time-synchronized long-distance quantum communication and novel developments in quantum hardware and quantum protocols. The goal of InterSync is not only to provide a demonstration and testbed for current quantum communication technology, but also to lay the foundation towards real-world implementations of more complex approaches, such as secure time distribution, blind computing, and secure authentication protocols.

• DFG Programme: Major Instrumentation Initiatives
• Major Instrumentation: Customized fiber-optic time and frequency distribution system ; High-Efficiency QKD testbed with picosecond long-haul synchronization
• Applicant Institution: Gottfried Wilhelm Leibniz Universität Hannover
• Leader: Professor Dr. Fei Ding
• Co-Investigators: Professor Dr. Ilja Gerhardt; Professor Andreas Wolfgang Schell, Ph.D.; Professor Dr. Reinhard F. Werner
• Cooperation Partner: Professor Dr. Stefan Kück