From theory to practice
For years, the idea of general-purpose quantum computers was merely a theory discussed in university laboratories. It is only in recent years that this theory has begun to be put into practice.
One of the most significant breakthroughs came in late 2019 with Google’s Sycamore quantum processor. Google said its 53-qubit device took just over three minutes to perform a calculation that would have taken the world’s strongest supercomputer at the time, Summit, 10 000 years.
In December 2020, China, known for its quantum technology investments, reported that its Jiuzhang quantum computer had performed in only a few minutes a calculation that would have taken a supercomputer 2.5 billion years.
Such improvements in performance demonstrate the possibilities that the future of quantum computing can bring.
Hakonen says that information security is one of the most obvious applications for quantum computing that will concern us all. The quantum computers of the future can crack the most employed encryption methods of today almost trivially using the so-called Shor algorithm.
All information encrypted at present can then be decrypted with ease, Hakonen observes.
Fifty Finnish qubits
No one can yet say with any certainty when the time of general-purpose quantum computers capable of cracking existing encryption methods will come. Data security solutions that can withstand the number-crunching abilities of quantum computers are already being developed.
In Finland, research is being carried out as part of the joint VTT Technical Research Centre of Finland, Aalto University and University of Helsinki project Post-Quantum Cryptography, for example.
This year will also see the completion of the first phase of a quantum computer commissioned by VTT. It is being delivered by IQM Finland, a firm that got started at Aalto University. This domestic quantum computer will represent an important milestone for Finnish quantum technology research.
The quantum device will be constructed at Micronova, the micro- and nanotechnology building at Otaniemi, and will at first have a capacity of five qubits, with the goal of increasing this to 50 qubits by the end of 2024.
The state-of-the-art scientific refrigerators, or cryostats, used to cool its quantum circuits will be supplied by the world-leading Bluefors company, which started out at the Helsinki University of Technology.
‘Bluefors emerged from our Low Temperature Laboratory some fifteen years ago,’ says Hakonen.
He points out that the vast expectations associated with quantum computers are evident both in heavy recruitment of researchers by companies in the field and the availability of early-stage capital investment.
‘How the industry will eventually develop is a more difficult question.’
From pharmaceutical research to flight control
Refrigerator-sized quantum computers won’t be taking the place of our laptops or mobile phones. Quantum computation requires carefully selected special problems that can be written as an algorithm utilising quantum properties.
The effect quantum computers will have on our daily lives will be based on the possibilities of high-performance computing.
Suitable challenges for quantum computers include research into new materials or chemical compounds. For example, it is difficult to model drug molecules efficiently with traditional supercomputers.
Hakonen says quantum computing is also a good fit for urban traffic flow management or climate change forecasting.
Known as a commercial pioneer in the field, the firm D-Wave Systems in Canada is already developing supersimulators that utilise quantum technology for use in, for example, flight control, an application area with complex optimisation problems.
However, while based on quantum cooling, D-Wave's solutions are not true quantum computers in the same sense as the VTT device.
‘There is no need for a general-purpose quantum computer in flight control. A system that can be programmed to handle the problem at hand is enough.’
As application areas expand, knowledge of the basics of quantum physics is needed in more and more professions. Aalto University is already offering a bachelor's programme in quantum technology.
According to Hakonen, there are also gaps in the teaching of this rapidly advancing field. For example, courses in quantum algorithms are not yet available.
‘We need programmers who know how to program quantum computers and sensors based on quantum technology.’
Quantum sensors, enhanced by quantum algorithms, are emerging as an important application area for quantum technologies. More accurate measuring devices offer possibilities in seismology, mineral exploration and material industry troubleshooting, for example.
One of the most exciting areas of application for quantum sensors is the human body. There are many gaps in our knowledge of the activity of the 86 billion neurons our brains are made of, for instance.
At Aalto University, for example, new types of head-adaptive sensors for measuring the magnetic fields of the brain have been studied. At best, the results are almost as accurate as taking measurements inside the skull.
Hakonen says that quantum-amplified sensors are, at this early stage, still so expensive that price limits their use. Later, however, application of the sensors may extend to mass products. In the VR realm, for example, exploiting them can open up entirely new dimensions.
When quantum-enhanced sensors that measure human brain signals are combined with interpretations produced by machine learning, the potential of quantum technology begins to sound limitless.
Hakonen thinks that one day we might control computers and other devices with our thoughts.
‘In the future, these technologies could potentially be used in brain interfaces as well – but that remains the stuff of science fiction for now.’