Dr Valentina Parigi: I currently work with multimode quantum optical fields and in particular, my project consists of arranging them in complex network structures, which are used in quantum information protocols. I’m really excited by the idea that complex network theory, which has been developed for real-world social, biological and technological networks, has turned out to be apt at describing our quantum optical systems.

Dr Ben Brown: My research, on quantum error correction, investigates how to build a large-scale quantum computer that can work in a noisy environment. This is a difficult but essential problem that still needs to be solved to realize useful quantum technologies. I get excited when I find new models from different areas of mathematics and physics that are useful for robust quantum computation.

V. Parigi: For quantum information encoding we use a strategy that exploits so-called continuous variables. Within this framework, a challenge remains in understanding the set of resources required to implement useful quantum protocols. Also, our experimental systems have a large set of degrees of freedom that can be exploited to build quantum networks. A major challenge is thus in developing experimental methods that are able to control and measure all of them.

B. Brown: We develop and design very abstract mathematical models for fault-tolerant quantum computation. We need to build these models in the laboratory and, ultimately, we need to fabricate them at large scale for commercial use. A major challenge we must overcome is building collaborations with experimental physicists. This is necessary for two reasons. First of all, we need to communicate new models to our colleagues that are working in the laboratory that can correct errors that physical quantum systems experience. It is also important to understand the hardware that can be constructed in the laboratory, together with its shortcomings. This allows us to develop fault-tolerant architectures that can compensate for the weaknesses of the quantum devices that we can make in the laboratory.

Dr Valentina Parigi is Associate Professor at Sorbonne University, working in the Multimode Quantum Optics Team of the Kastler-Brossel Laboratory.

Dr Ben Brown is a theoretical physicist and research fellow at the University of Sydney.