Are we at the dawn of a quantum era?

Quantum computing has gone a long way, from the dream of Richard Feynman with his keynote speech of 1981, to the increasingly sophisticated theoretical developments that followed in the 90s, to the early realizations of experimental quantum bits in the past 20 years. Today we start to see the first machines sporting some tens of qubits connected by fully reversible quantum gates, which attempt at solving theoretical benchmark challenges. It is not still the calculation of real-life problems, however they are getting a bit closer every few months, in a path that seems to echo the spectacular growth of microelectronics.

Google reported reaching “quantum supremacy” in 2019, a claim later challenged by IBM engineers. Both IBM and Google use qubits made with superconducting devices. IBM just announced its new milestone a couple of weeks ago, with a 127-qubit device. In June, the US Senate passed a 5-year, $250 billion "Innovation and Competition Act", among which an important quota will be devoted to quantum information technologies. At the other shore of the Pacific, with a multi-billion-dollar funding package at the same level including a €10 billion investment in a quantum information laboratory, China hopes to make significant breakthroughs in the field by 2030. Already a team at the University of Science and Technology of China in Hefei reported achieving quantum supremacy with two different technologies, using linear optics or superconducting qubits, just one year apart from each other.

As far as Europe, in October 2018 the European Commission launched the Quantum Technologies Flagship programme, to support quantum science research over a ten-year period with a budget of €1 billion. UK has announced conspicuous investments, while it relies on the technology provided by the US start-up Rigetti. Germany followed a similar strategy, coupling €2 billion in national investment with US quantum technology imported from IBM. France follows, as usual, a more original way, with the home development of a large-scale quantum annealer (a somewhat different concept from the logical gate based quantum computer) by the start-up company Pasqal, in parallel to a 5-year €1.8 billion funding, half of which public.

What could be the role of a big institute like the IEMN in such a “rat race”? We are already working on a few projects in closely related areas of quantum devices, sensors and materials, but should we look for a place also in this emerging field of quantum computing? Many research groups around the world are gaining a conspicuous advantage both in the design of hardware systems and of basic quantum algorithms. If we want to make an investment, a successful niche can probably be found in the development of specific applications, a middle ground that is just starting to blossom. Just like in the 60s the development of high-level languages such as Fortran made it possible to disconnect the applications from the hardware, by introducing a symbolic layer to be translated into machine language and then into binary code, the development of symbolic quantum coding standards will allow to write code independently of a specific qubit hardware. Already quantum simulators are being written in Java, C# or Python, and one can test relatively simple programs that can run on a real quantum computer, without any working knowledge of quantum mechanics. Future software engineers will be able to write quantum code just like today programmers write high-level applications, without minding at how a transistor or an operational amplifier actually function. 

It is therefore important to identify among our many current and near-future projects, some representative applications susceptible of translating into a quantum-based simulation, and most certainly not limited to fundamental research problems. These can be very different, e.g., from signal processing to network optimization in public transport, from multi-physics multi-material devices to molecular interaction networks, and more. These reflections should be done at the right time, for example by creating open discussion groups, if we want to jump on the leading wagons of the quantum train.

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Director of publication: Thierry Mélin
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