Quantum computers are arguably something to count on. When we’ll start using them may be anyone’s guess, but we do have an idea as to how. Just like quanta that can have multiple states at once, their uses are not only manifold, but also ambiguous. On the upside, a quantum leap in performance means that we’ll be able to solve increasingly complex problems. On the downside, it allows every current encryption mechanism to be cracked. The question is who will get there first?
In 2019, Google claimed that its quantum processor Sycamore had been the first to achieve quantum supremacy by solving a calculation that would have taken the world’s fastest supercomputer 10,000 years to finish. If that is actually correct is still being debated. All the same, the fact that Sycamore was able to present a result within 200 seconds is an incredible breakthrough—a real eureka moment. The next goal is to enhance the stability of these delicate quantum states so that they behave as we would like them to.
A quantum bit, or qubit for short, can exist as both 0 and 1 at same time—unlike the common bits we’re used to today. This dual state is called superposition. By superposing several qubits, these states can be multiplied further. Algorithms can leverage qubits to process data in parallel and at breakneck speeds with performance increasing exponentially with each additional superposed qubit. Sycamore’s record stands at 53 qubits. The error rate stands, however, at 0.3% resulting in three out of every one thousand calculations being incorrect. That’s too many to be considered reliable.
One result that has come out of Google’s research is that quantum technology has reached a wider audience. It has been widely reported, which is the basis for meaningful debate about potential uses, challenges and risks. One thing we know is that quantum computers can process huge amounts of data and handle complex, changing dependencies. Possible use cases include road traffic management, logistics, and developing pharmaceuticals that are tailored to the individual health needs of patients. In theory, we could use the technology to tackle all new challenges and find solutions in chemistry, biology and physics and perhaps create previously unimaginable materials. Another potential benefit is in complex market analytics, e.g. for financial markets, and in the continued development of artificial intelligence and machine learning.
Quantum cryptography and Quantum Key Distribution (QKD) is already being used on a small scale by banks and governments for highly secure data transfers. In layman’s terms, the superposed quantum objects, e.g. photons, are measured at two different locations. If certain parameters are determined to be correct, this confirms a secure connection. The range of QKD applications using fibre connections is, however, still limited. Here’s the kicker: Unlike common cryptography—and as with all things quantum technology—it’s not mathematic principles, but rather physical laws of nature that form the foundation.
The potential for this technology to be used for decryption is a serious drawback, though. A functional quantum computer would easily be capable of “working out” traditional ciphering methods. But that’s not yet possible and it’s assumed that computers with at least several thousand qubits would be needed to do the job. Apart from that, the amount of energy that would theoretically be needed is ridiculous. Still, there are worries about the potential future decryption of keys that were designed to secure information in the long term, such as in satellites. That’s why there’s work being done already on post-quantum cryptography as a defence against hypothetical attacks from quantum computers.. The German pilot project QUBE has been set up with the aim of creating a QKD-secured satellite platform
Computers, communication and also metrological applications are being intensively developed with the help of quantum physics. The amount of global resources that have been invested is huge with the USA and China leading the way, and countries are racing for the best cryptographic defences. But there are also vast opportunities to elevate whole technological areas on the horizon. A broad field of possibilities to be researched offers exciting perspectives that we should all pursue—even when it seems a little over our heads. These tiny particles are a very big thing indeed.
Europe is considered a world leader in quantum physics with some 50% of all related scientific publications and nearly 40% of all researchers in the field. The situation in Germany looks good, too. The federal government has defined a framework programme with concrete steps and goals, making €650 million available for research purposes in the current legislative period. A wide range of research institutions are also on board—from the Max Planck and Fraunhofer Societies to the Helmholtz Association and the German Research Foundation among others. Strategic partnerships are also playing a role in driving forward development. For instance, the German Armed Forces are teaming up with IBM to set up a quantum hub at the Cyber Defence CODE research institute in Munich.
Published on Apr 15, 2020.