by Shaukat Ali (SIMULA) and Sølve Selstø (Oslo Metropolitan University)
The development of quantum theory, which started early last century, has had an impact that can hardly be overestimated. Within the fields of physics and chemistry, it has been a true game changer; but its impact is broader than this. Our new knowledge about the nature of matter has had vast implications for our understanding of nature itself. And quantum theory has brought about new technology – such as microscopy and metrology with unprecedented resolution, lasers, spectroscopy, nuclear magnetic resonance imaging, and semiconductor-based technology, to name a few.
Moreover, a few decades ago, the idea of using quantum physics to process information was born. In theory, the potential was enormous, due to the ability to process vast amounts of information very efficiently. The problem is, of course, that quantum systems tend to be delicate; running elaborate quantum programs on physical implementations while preserving the quantum nature of the system is a challenge. Making actual hardware that could harness the quantum advantage, at the time, seemed like a pipe dream.
However, recent technological breakthroughs provide reasons for optimism. The field of quantum information technology, including quantum computing (QC), is now flourishing. There is bona fide hope that QC may be able to solve important real-life problems that are beyond the capacity of traditional information technology.
The advancement of quantum technology and quantum computing requires research and development work from a wide range of fields. We still need new theorems and algorithms, and we need to consider various physical implementations of quantum bits, qubits – both theoretically and experimentally, in addition to finding novel technical implementations of those being tested. On the software side, we need to develop novel ways of coding, testing, simulating and optimising quantum algorithms. We need to investigate the potential for solving real-life problems with the quantum resources available both now and in the future. And we need to find best practices in educating the next generation of quantum programmers. The advancement of quantum information technology engages mathematicians, logicians, physicists, chemists, engineers, informaticians, software developers, consultants, teachers and others. It is a pleasure to see this diversity reflected in the contributions to this issue of ERCIM News.
Interest in QC is growing globally and Europe is no exception, with several major initiatives underway. For a start, the EU Quantum Flagship FET program [L1] is pledging at least one billion Euros in quantum technologies. In addition, several European quantum computers are being developed, such as by IQM and VTT in Finland [L2], OpenSuperQ [L3], and AQTION [L4]. Moreover, ATOS [L5] is selling specialised quantum learning machines to facilitate rapid development, research, and education in quantum computing. Furthermore, high-performance computing facilities, such as eX3 [L6] in Norway, provide access to quantum computer simulators. Last, but not least, Fraunhofer installed an IBM quantum computer to accelerate the development of quantum technologies in Germany. In addition, alliances are being built: NordIQuEst is a Nordic–Estonian consortium to pool quantum computers and related resources. These computing resources will be accessible to the participating countries for research, teaching, and developing business development plans.
This ERCIM News’s special issue about quantum computing features 25 articles that cover this topic from nine perspectives, as summarised below:
Quantum software is at the forefront of programming quantum computers to build practical applications. Cost-effective development of quantum software is often supported by a complete software stack starting from high-level languages to execution on quantum computers/emulators. However, standardisation is key for a broader impact, as discussed in Bock et al. Moreover, as highlighted in the article by Nurminen et al, quantum software presents a significant bottleneck for the success of QC after quantum hardware. Thus, the University of Helsinki, Finland, is pushing the boundaries of quantum software in many dimensions. A novel proposal also comes from the University of Torino in Italy, where programming languages for near-future quantum computers are studied, with emphasis on interactions between classical computers and quantum co-processor (Damiani et al) Finally, researchers at Aarhus University, Denmark, are investigating the control of quantum systems with Alpha-Go, which is essential to build many envisioned quantum technologies (Dalgaard and Sherson). Finally, to ensure the correctness of quantum software-based applications, Simula Research Laboratory, Norway, is developing novel automated testing and debugging solutions for quantum software (Yue and Ali). At the same institution, the eX3 infrastructure is used for quantum emulation (Denysov et al.), while researchers affiliated with the Quantum Information National Laboratory of Hungary report the development of an efficient simulator of photonic quantum computing (Rakyta et al.).
Quantum software implements quantum algorithms that realise quantum applications. For example, researchers at the Institute for Computer Science and Control, Hungary, are investigating new algorithms for computational algebra and machine learning (Ivanyos et al.). Similarly, at the Institute for Quantum Computing and Infinite Potential Labs in Canada, algorithms for solving different types of differential equations are being studied (Fillion-Gourdeau).
Security and safety of quantum computing
Quantum computations will soon be accessible through on-demand services; therefore, security and privacy requirements will need to be ensured. Researchers from Inria, France, report their results on embedding security as part of quantum hardware, in addition to quantum networks ensuring the security requirements (Garnier and Olivier). The need to perform computation on untrusted servers is also highlighted in the article by Hrdá. To this end, the Fraunhofer AISEC, Germany, is investigating the development of secure and safe quantum computers to enable trustworthy QC.
Quantum computing benchmarking
Researchers from the University of Thessaly in Greece are working on benchmark quantum computing devices. Such benchmarking is essential to enable us to evaluate and compare quantum devices to assess their performance in solving problems (Savvas and Galanis).
Quantum computing applications
With the hope that novel quantum solutions will soon find their way into practical applications, several interesting ideas for quantum applications have been proposed. A novel approach involving quantum walks for modelling autonomous driving is presented in the article by Karafyllidis, while Halffmann et al. outline plans to apply quantum computing to improve energy market modelling. As described in the article by Bartsch et al., the quantum version of the much-applied Fourier transforms bears promise of finding several industrial applications.
Joint ventures and initiatives
To advance quantum computing and promote the quantum cause, researchers and research groups have been establishing joint projects, centres and other initiatives. Several of these are introduced in this issue, including the SEQUOIA project (Tutschku and Stephan), the Nordic-Estonian Quantum Computing e-Infrastructure Quest (Johansson and Wendin), the Quantum for Life research centre (Nielsen), and the QSpain think tank (Arias et al.).
Quantum computing will eventually need to be enabled on the internet to support, e.g., distributed quantum computing. However, the classical internet is not sufficient to transport quantum states. Thus, researchers from Institute for Informatics and Telematics, Italy, are researching quantum networks with the long-term goal of establishing a quantum internet; the security of such networks is their core agenda (Cicconetti et al.). The Fraunhofer Competence Network Quantum Computing is also investing in network German quantum computing resources intending to support real-world applications of QC (Behlau and Venzl). Fraunhofer took the major step of installing a quantum computer by IBM in its premises in Ehningen, Germany, with the objective of providing access to this technology to relevant partners who wish to develop QC applications through the competence network.
Quantum computing education
With quantum computers becoming available, there is a need for professionals who can program them. As pointed out by researchers from Fraunhofer AISEC (Simić and Hrdá), this need must be identified and recognised by those who educate the next generation of computer engineers and scientists. A relevant question in this regard, as addressed in the article by Bungum and Selstø, is whether students should be familiar with quantum physics in order to learn quantum computing.
Quantum computing hardware
If existing prototypes are anything to go by, superconducting Josephson junctions seem to be the most promising implementation of quantum bits. However, promising alternatives are still on the table, such as implementations involving photonics, as in the article by Thanopulos et al., or spin (Mitrikas).
The wide range of articles from different perspectives in this special issue highlights the promising future of quantum computing in Europe. Furthermore, the contributions of researchers from various fields, including physicists, mathematicians, software engineers, computer scientists, and educational researchers, show that experts from many domains are aware of quantum computing’s importance in the future. This awareness will enable quantum computing to deliver applications in many fields.
Shaukat Ali, SIMULA, Norway
Sølve Selstø, Oslo Metropolitan University