A quantum leap for quantum technology

The quantum technology flagship of the European Commission was launched in October 2018. Spanning ten years, the research programme will use grants totalling one billion euros to promote the development of products based on the rules of the exotic quantum world. The federal government will additionally contribute some 650 million euros during the current legislative period. Prof. Tommaso Calarco from the Peter Grünberg Institute in Jülich is one of the intellectual fathers behind the initiative. With two of his colleagues, he published the “Quantum Manifesto” in the spring of 2016. Some 3,400 science and industry representatives signed the twenty-page paper calling for a European initiative on next-generation quantum technologies. Our author Arndt Reuning talked to the physicist about the content orientation of the flagship programme’s first funding round.

The European flagship programme is to help develop “second-generation quantum technologies”. What does that mean?

Many applications and products of our daily life today are already founded upon the effects of quantum mechanics. Without them, transistors, lasers and computer processors would not be conceivable. However, all these technologies are based on the fact that we use a large number of atoms, electrons, photons or other particles with them. The second quantum revolution, which is currently taking place, manipulates individual quantum objects. Let’s take communication as an example: nowadays, messages are transmitted bit by bit with laser pulses via fibre optic cables. These messages can be intercepted. All I have to do is take a few photons from the laser pulse. But if I send, per bit, only a single photon, a single quantum, then this cannot be divided any further. An eavesdropper would have to intercept the photon itself. But he would change it in doing so and thereby give himself away. Communication via individual photons therefore means the highest degree of security for data transmission.

The development of a quantum computer that is clearly superior to today’s supercomputers, at least for some tasks, is considered to be the “Holy Grail” of quantum technology. Is that one of the targets of the quantum flagship, too?

Oh yes, quantum computing is one of the programme’s four pillars. This is certainly a great, long-term vision, but also an extremely exciting application. Computers calculate with the bit as the smallest unit of information. In the quantum world, particles carrying information are no longer subject to the classical laws of the macroscopic world. Their states can overlap. Accordingly, bits in the quantum world – so-called qubits – can assume any value between zero and one. In addition, two particles can be entangled with each other. They are then connected to each other as if by an invisible ribbon. Albert Einstein once called this the “spooky action at a distance”. These effects are responsible for the extraordinary computing power of quantum computers, which should enable them, for example, to override the standard procedure for encrypting data on the Internet. They have not yet reached that point, but soon they should be able to play to their advantage in this respect. That would be a quantum leap in computing power in the truest sense of the word.

Sie haben erwähnt, dass das Quantentechnologie-Flaggschiff auf vier Säulen steht. Welche sind das noch?

Neben dem Quantencomputing und der sicheren und schnellen Kommunikation geht es noch um die Simulation von komplexen Materialien mit Hilfe vereinfachter Quantenmodelle. Das könnte zum Beispiel die Entwicklung neuartiger Materialien fördern. Und die vierte Säule bildet der Bereich der Sensorik und Metrologie. Dabei geht es zum Beispiel darum, hochgenau Messgeräte zu entwickeln, welche die Gehirnaktivität in Echtzeit aufzeichnen können. Das würde uns dabei helfen, neurologische Krankheiten besser zu verstehen und möglicherweise auch zu heilen. Außerdem könnten uns Quantentechnologien dabei helfen, unsere Navigationsgeräte zu verbessern. Wir navigieren heutzutage aufgrund von Satellitensignalen, deren Genauigkeit von Atomuhren abhängt. Wenn wir für diese Uhren einzelne, verschränkte Atome als Taktgeber nutzen, lässt sich ihre Präzision noch einmal deutlich verbessern. Ich wüsste dann ganz genau, wie weit mein Auto vom Straßenrand weg ist oder von anderen Autos. Das wäre enorm wichtig für autonomes Fahren. Also: auch jenseits des Quantencomputers verfolgen wir im Flaggschiff-Programm Ziele mit großer gesellschaftlicher Relevanz.

But aren’t we still in the field of basic research these days when it comes to quantum technologies? How can the transition to industrial applications be successful?

This is exactly what the flagship programme is all about. In Europe, we have reached a level of maturity in terms of science that enables us to translate this knowledge from the research laboratory into products. We have a high level of scientific excellence, but not until recently did we have the relevant involvement of industry, so that we would run the risk that the knowledge that has been initiated here in Europe would be transformed into products and economic growth elsewhere. We were aware that we had to act now. Because of the very strong competition from private and public donors outside Europe, there would otherwise be a danger for us to be left behind internationally. With the flagship programme, however, we have now set the right course. Basic research will continue to be important, because scientists need freedom to pursue ideas simply because of their curiosity. This results in findings that will later lead to applications. Basic research, thus, is the foundation for the four thematic pillars.

Where do you see the big challenges ahead of you?

We have now received a very large financial boost from both the European Commission and the German Government. Now we must endeavour to fill the research programme with life and to bring innovations to the market. Questions of robustness are also involved here. A high-precision sensor must not only work under controlled laboratory conditions, but also as a small, inexpensive chip on my mobile phone. To achieve this, quantum researchers and engineers must move towards each other in order to develop user-friendly products. We must therefore ensure that academic training is also adapted: we need degree programmes in quantum engineering. This will also be an important part of the quantum flagship.

Arndt Reuning