Leibniz universität Hannover (LUH)
Quantum communication is one of the most promising technologies of our time. It promises the theoretically complete secure encryption of messages, regardless the available tools of the potential adversary. The security of quantum key distribution (QKD) is based on the laws of quantum mechanics, which are skillfully exploited to detect whether the communication line used for key transmission is being intercepted during encryption. In addition, quantum communication enables the secure connection of future quantum computers at different locations, allowing their computing power to be combined (distributed quantum computing). Together, these aspects form the vision of the quantum internet.
The research group of Prof. Fei Ding is working on precisely this vision: they are developing and testing so-called semiconductor quantum dots, which will play a key role in the physical realization of the quantum internet. As they can function both as single photon or entanglement sources and as quantum memories, they have all the properties required for so-called quantum repeaters. These will enable efficient quantum communication over any distance and thus play a decisive role in the establishment of a Germany- and Europe-wide quantum network.
On the way to this goal, they unite a complete research infrastructure under one roof. They are part of the “Niedersachsen Quantum Link” fiber network – a fiber testbed that connects several research institutions in Hannover with the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig. This network makes it possible to test newly developed quantum repeater components and state-of-the-art QKD protocols and systems efficiently and realistically. The testbed was recently used to demonstrate the world’s first quantum communication experiment with a real semiconductor single photon source between two cities as well as quantum-based time and frequency synchronization.