Will quantum computing ever solve real-world problems?
The world of quantum computing is so complex and ambitious that some might think it belongs to the realms of science fiction. But, as physicists John Martinis and Ian Walmsley tell Zero Pressure podcast host Helen Sharman, quantum computers could have huge implications for the likes of AI, transport logistics and defence & security.
Quantum computing has only been around since 1980, but it’s a rapidly emerging technology and some are already expecting it to produce big things. It focuses on developing computer technology based on the principles of quantum theory, which explains the behaviour of energy and material on atomic and subatomic levels.
While classical computers encode information in binary form of 1s and 0s, quantum computing uses quantum bits or qubits, giving it the possibility of using the unique ability of subatomic particles to exist in more than one state, as 1s and 0s at the same time. The potential for quantum computers to solve problems that are too complex for the classical computers of today raises hopes that this technology will have profound effects on society.
Breakthroughs in medicine through research into new molecules; solving complex logistical problems of transport systems and manufacturing; further development of AI; and advances in secure communications for the likes of the aeronautics and defence industries: all are mentioned as potential benefits that could be within our reach within the next couple of decades.
In a fascinating discussion, former astronaut Helen Sharman hears from John Martinis, Professor of Physics at the University of California at Santa Barbara, and Ian Walmsley, Provost of Imperial College London and Chair of Experimental Physics. They caution that there is still much development needed before we see machines that can produce tangible applications to aid society. Nevertheless, both are optimistic that this day will come.
“Machines now can solve interesting and important problems, but not yet ones that can have a direct public benefit,” says Ian Walmsley. “But we are in the stages of scaling up.”
The progress so far
Quantum computing has already come a long way from the initial idea raised by physicist Paul Benioff in 1980, but, say Martinis and Walmsley, it is still at an experimental stage. Probably the biggest step forward came with the achievement of quantum supremacy in 2019, where a team from Google AI quantum demonstrated that a programmable quantum device was able to solve a mathematical problem that was beyond the capabilities of state-of-the-art classical computers. John Martinis was a key member of that team.
“The quantum supremacy experiment was to show that quantum mechanics works, and you can build a system,” says Martinis.
“We’re making steady progress and that was a big milestone, but we need more innovation and to overcome some of the challenges including (in the case of the superconductivity platform used by Martinis), the need to work at extremely low temperatures.”
Other challenges include the incidences of errors in the existing test technologies, and the issues of absorption and unpredictability that affect the use of photon platforms in optical computers, in which Ian Walmsley specialises. The energy consumption of machines that could be the size of houses is something else to grapple with.
Nonetheless, as Walmsley points out, there has already been a lot of public and private money invested in research into the technology, which spurs on competitive creativity, inching us further towards, one day, serial applications.
“The UK has committed to investing GBP 1 billion over the past few years, the EU Quantum flagship programme has €1 billion investment and the US National Quantum Initiative has invested USD 1.5 billion,” says Walmsley.
“There are also big programmes in Singapore, Europe, Canada, Australia and Japan, while the Chinese effort is concentrated in their national institutions and universities. There’s been a significant amount of public money committed to this and there are also a number of big corporations investing, including Google, IBM, Microsoft, as well as private venture capital going into start-ups. By the time you add all that up, it adds up to real money.”
While it may not be around the corner, some experts believe it could be possible in the near future for quantum computing to address climate-related issues through the use of new chemical algorithms to improve plant yields, better fertilisers and better pesticides. Also on the horizon is the use of quantum computers to optimise complex logistics for both aerospace and defence and transport.
In fact, says Ian Walmsley, simpler types of machines for random number generation are already being sold. These could potentially be used in market simulations to generating code pads for secure communications.
“Quantum computers will follow the same trend we have seen with desktop computers,” says John Martinis. “The complex programmes will be in data centres and we’ll remotely access them in the way that we remotely access any powerful programmes right now. That will be how normal people – not those working in government institutions or research labs - use quantum computers.”
“Google hopes to build a million-Qubit machine by the end of this decade,” he adds.
“There are many people working hard on quantum computing technology. It could have a very big impact on the world.”