Group leader  : Nicolas Sangouard
Institut de Physique Théorique

As a nonlocal theory, quantum mechanics differs radically from classical physics. How can quantum properties, such as nonlocality, be useful in the scope of information theory? This question is at the heart of our research activities. Several research directions are explored, covering different fields of fundamental and applied physics. 

In particular, we are interested in the use of nonlocal correlations for the certification of quantum technologies. How to extend a random bit string in a reliable way? How to guarantee the security of a quantum key generated with unknown devices, which are treated as black boxes? Can the quantum aspect of a simulator be certified without knowing the size of the underlying Hilbert space or the internal workings of the devices used to characterize it? We are developing tools such as Bell tests – which were initially proposed to detect nonlocal correlations – to answer these questions. The short-term goal is to better understand the limitations and possibilities of these tools. In the long term, we could develop a new mathematical framework to certify the most advanced quantum technologies, using a minimum of assumptions about how they operates. 

Most of our projects are carried out in close collaboration with numerous experimental groups, mainly based in Europe. We propose experimental research programs in quantum information, we guide the corresponding experiments with the help of quantum optics tools and we support the experimentalists in the analysis of the results, using statistical tools. This unique mix of fundamental and applied projects using advanced theoretical tools from different fields of research, as well as close collaborations with different experimental groups, gives us an ideal environment for improving and advancing quantum technologies.