"What kind of computer are we going to use to simulate physics? Can you do it with a new kind of computer – a quantum computer?"
Richard Feynman, 1982

Advances in technology since the 1960s have enabled silicon transistors to keep shrinking, allowing exponential growth in computational capability. However, they are now so small that the laws of quantum mechanics begin to impair their performance and cannot shrink much further. The continuous breakthroughs in science that have been enabled by this computing growth are now becoming limited. However, with an understanding of quantum mechanical behaviour, new possibilities for computation are being explored. Can the computer postulated by Richard Feynman now be realised? A computer that relies fundamentally on quantum mechanics can potentially solve many important computational problems faced by businesses that will remain forever intractable using conventional computers.

"For me, quantum computing is the answer to the question ‘how do we maximally harness the laws of nature to process information'?"
Dr Peter Leek, Department of Physics and founder, Oxford Quantum Circuits

### The global race

Quantum technologies utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing. However, a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been identified in which they survive long enough and are sufficiently controllable to be useful.

In 1999, the world’s first quantum computing company D-Wave Systems Inc was spun-out from the University of British Columbia, founded by two physicists and a local venture capitalist who provided the first USD3,000. Twenty years later (and despite scepticism from the quantum computing community), the company have gone on to raise more than $200m including investments from Jeff Bezos, founder of Amazon. Their first customer was Lockheed Martin, who were looking for a way to tackle particularly tough optimisation problems in their flight control systems, followed by Google and NASA. Although D-Wave were the first to market, there is a bigger story developing, with the UK and Oxford's Department of Physics among the leaders in creating a quantum technology industry. "We could map the whole Universe — all of the information that has existed since the Big Bang — onto 300 qubits." Seth Lloyd, MIT To support and capitalise on the UK’s world-leading academic quantum physics research, the government announced a £270m five year National Quantum Technologies Programme in 2013, which aimed to accelerate commercialisation by creating a coherent community, involving more than 130 companies, 17 universities and various government agencies. Four research hubs were created to support collaboration and to provide facilities and training, focused on applications in timekeeping, sensing, imaging, communications and computing. Oxford's Department of Physics led the Networked Quantum Information Technologies Hub (NQIT), bringing together researchers from the Departments of Physics, Engineering, Materials and Computer Science at Oxford and other universities, with the aim to prototype the basic components of a quantum computer. But the UK was not alone in this investment, with the international race for quantum technology underway and attracting enormous research funding including$1B over 10 years in Europe, $4B over five years in China,$1.2B over five years in the USA and hundreds of millions of dollars by several multinational companies including Microsoft, Google, IBM and Intel.

The goal of NQIT was, in collaboration with government, industry and the wider community, to develop the first truly scalable universal quantum computing machine with architectures that have the highest performance of any current qubit system. Aligned to this was the aim to build a new industry sector around quantum information technology, from the supply chain, through the build and operation, to programming and use of quantum computers. The NQIT consortium saw an alliance of nine universities led by Oxford, plus more than 30 commercial and government organisations including IBM, Lockheed Martin, Raytheon, Google, Toshiba, Oxford Instruments and the National Physics Laboratory.

### Oxford inventions

Qubits in superposition are extremely sensitive to external stimuli, with the slightest disturbance causing them to collapse, introducing errors into the calculations being carried out. Adding extra qubits to a system and getting them to talk to one another, and thus build a computer that can crack the toughest calculations, is a significant challenge in physics and engineering. Oxford physicists are pioneering two different technological approaches for the ‘processors’ that could form a quantum computer, with each looking for the balance between ease/cost of manufacture and fidelity (its resistance to decoherence). One method being developed here uses superconducting circuits for the quantum computer’s architecture. This approach exploits the quantum mechanical behaviour of electrical circuits when operated at microwave frequencies and at a temperature near absolute zero and has been used by companies such as IBM and Google for their quantum computing systems. To support further development of Oxford’s intellectual property in this area, a spin-out company, Oxford Quantum Circuits, was founded in 2017 by Dr Peter Leek, to build scalable components for a quantum computer.

Another method has each processing node as an ion trap, within which a small number of ions are held suspended in a vacuum. A qubit is embodied within the internal hyperfine states of each ion, and control of the qubits is achieved optically via integrated lasers and through microwave manipulation. This technology has also attracted significant interest from investors and in 2019, a spin-out company, Oxford Ionics, was founded by Dr Chris Ballance and Dr Thomas Harty from the ion-trap group, to take forward its commercialisation.

### Creating a quantum future

The Government Office for Science predicts that quantum technologies could grow to be comparable in size to the consumer electronics sector (currently worth an estimated £240bn a year globally) and potentially create hundreds or thousands of high value jobs in the UK. To realise this potential, the UK government’s National Quantum Technologies Programme has now entered its second phase of funding, a £315 million investment in a National Quantum Computing Centre and four research hubs, including a Quantum Computing and Simulation hub led by Oxford University. This hub will bring together research teams across 17 universities with more than 25 national and international commercial, governmental and academic entities.

Alongside the hardware development, researchers are developing the software systems to program and operate a quantum computing machine and are working on our own quantum computing emulator platform for high performance computers, which will enable scientists in research and industry to develop algorithms and applications for the emerging hardware.

“The quantum computing and simulation hub will drive forward the UK’s progress in developing future quantum computing technology. It will build on the successes of the Oxford-led ‘Phase 1’ NQIT hub, which has delivered world-leading performance in quantum logic and quantum networking, as well as a number of spinout companies to take quantum research out of the lab into the commercial arena.”
Professor David Lucas, Department of Physics and principal investigator, Quantum Computing and Simulation hub

Engaging with the future users of quantum computers both in academia and industry has been a central part of NQIT’s mission from collaborations with the supply chain to supporting and engaging with the emerging software sector to growing a base of skills and awareness. The new hub will continue this work of helping businesses prepare for all aspects of the emerging quantum information technology economy. Oxford University’s leading role has opened the possibility of the region becoming a UK home for this revolutionary technology, with significant investment in our research and university spin-outs, as well as local start-ups, that will build the components and capitalise on its capabilities. Are you quantum ready?