QUROPE Quantum Information Processing and Communication in Europe

Location

Coherent optics has been known since the 1960’s to be, in principle, the best tool to achieve very high bandwidths and bit rates in optical communication. While the development of fiber optical amplifiers in the 1980’s has reduced the need for developing such a technology, the advent of quantum information sciences has triggered a renewed interest in using coherent optics to realize high-rate quantum communication systems. The present project is focused on coherent quantum communication as a way to combine the intrinsically very high rates achievable by homodyne or heterodyne detection with the fundamental benefits of using quantum mechanics such as unconditional security. Unlike with classical communication systems, an optical amplifier cannot be used as a repeater in a quantum communication setup because it is inherently limited by quantum noise. The thrust of this project is to explore different techniques aiming at circumventing this problem and improving the range of coherent (also called continuous-variable) quantum communication systems, with a special emphasis on today’s most developed platform towards practical applications, namely continuous-variable quantum key distribution.

Different strategies will be followed in order to attain this goal, ranging from the use of classical coding and other post-processing algorithms, which is the most directly applicable solution in the short term, to more elaborate longer-term techniques relying on specific quantum optical schemes and ultimately on the use of quantum coding. In particular, the potential solutions offered by the heralded noiseless linear amplifier, or other non-Gaussian heralded operations, will be investigated in detail.

The specificity of our consortium is to combine the strength of 5 academic groups having an outstanding track record in the area of coherent (continuous-variable) quantum information science, including 2 theory (ULB, UY) and 3 experimental (IO, MPL, TPT) groups, together with 1 industrial partner (SQN) who will naturally orient the research towards the needs of the information society. We envision that this synergy between applied and fundamental – both theoretical and experimental – teams will be highly stimulating and productive, and will reinforce European competitiveness in information technologies.