Quantum Communication

Quantum communication is the art of transferring a quantum state between distant locations, either to transmit information, or distribute resources such as entanglement and nonlocality. Our work takes advantage of the close connection between theory and experiments in quantum optics and quantum information science that allow us to study fundamental concepts of Nature at the same time as advancing towards complex quantum networks, device independent quantum processing and a future quantum Internet.

Quantum communication is one of the central themes in our group. We have performed experimental demonstrations of seminal QKD experiments under lake Geneva to teleportation experiments in real-world communication networks. Central to many of these endeavours are the concepts of entanglement and nonlocality - we see these as a resource and providing the foundations for diverse quantum applications. We are working on different types of entanglement and different systems to demonstrate this, not only in the lab but also with the view that, to be useful, it has to survive in the real world. This requires making some compromises, but often, this has also pushed us towards new and exciting directions and opened up opportunities to perform foundational experiments, or on the other end of the spectrum, industrialise quantum technologies.

Recently, the concept of Device-Independent, or Self-Testing, quantum systems has been proposed, again a concept that bridges fundamental and applied physics. This is a so-called black-box approach to security with the goal being to ensure the security, the correct functioning, of quantum devices even if we do not know what is inside. These new concepts place extremely demanding constraints on all the component technologies, such as quantum photonics and photon detectors. We are working to realise these extremely challenging levels of control, while also bridging the gap to more practical quantum cryptography schemes.

Contact: Rob Thew

Team: Rob Thew, Hugo Zbinden, Anthony Martin, Melvyn Ho, Ephanielle Verbanis, Farid Samara

We have close collaborations with the Optics group of Nicolas Gisin and Mikael Afzelius, as well as the Quantum Correlations group of Nicolas Brunner.