Why do you need a quantum computer? Well, you don’t – unless someone else has one. And if they have a quantum computer, you’ll want one too. Driven by the promise of new technologies that will deliver benefits for all of society, nations around the world are investing heavily in the field. When it comes to quantum computing, no-one wants to miss out – and that desire is triggering a kind of global arms race.

While a standard computer handles digital bits of 0s and 1s, quantum computers use quantum bits or qubits, which can take any value between 0 and 1. And if you entangle the qubits, you can solve problems that classical computers cannot. A future quantum computer could, for example, crack any of today’s common security systems – such as 128-bit AES encryption – in seconds. Even the best supercomputer today would take millions of years to do the same job.

I’m delighted that here in the UK, construction of the new National Quantum Computing Centre will start this year

The US National Institute of Standards and Technology has already said that quantum computers will be able to crack the existing public-key infrastructure like 128-bit AES encryption by 2029. That prospect means businesses and governments are scrambling to improve the security of conventional networks, for example by using quantum-key cryptography. That’s a new market for quantum technology that’s expected to be worth anything from $214m to $1.3bn by 2024 (depending on which market survey you read).

Important investments

With all that in mind, I’m delighted that here in the UK, construction of the new National Quantum Computing Centre (NQCC) will start this year. Thanks entirely to a £93m investment from UK Research and Innovation (UKRI), the centre is being built at the Harwell lab of the Science and Technology Facilities Council in Oxfordshire. When it opens in late 2022, the NQCC will bring together academia, business and government with the aim of delivering 100+ qubit user platforms by 2025, thereby allowing UK firms to tap fully into this technology’s potential.

The NQCC is part of a £1bn, 10-year investment by the UK’s National Quantum Technologies Programme, which was launched by the UK government in 2013. It has already created a national network of quantum technology hubs in quantum sensors and metrology (Birmingham), quantum communications (York), quantum enhanced imaging (Glasgow), and quantum IT (Oxford). Seeking to develop and commercialize new technology, the hubs are part of a growing quantum industry in the UK that saw more than 30 quantum start-ups founded by the end of 2019.

The visionaries behind the programme were none other than Peter Knight – a former president of the Institute of Physics (IOP) – and David Delpy (the IOP’s current honorary treasurer). The potential benefits of quantum technology to the UK economy were discussed at an online seminar run by the IOP’s Business Innovation and Growth group, which featured the IOP’s current president elect, Sheila Rowan, as well as Knight and the UKRI’s “challenge director”, Roger McKinley.

To do something really useful with quantum computers will require significantly more than 50 qubits

Last year, researchers at Google claimed that their Sycamore processor, which has 53 superconducting qubits, was able to verify in just 200 seconds that a set of numbers was randomly distributed. The same calculation, the firm said, would take 10,000 years on IBM’s Summit machine, which was the world’s most powerful supercomputer at the time. IBM hit back, insisting that, with some clever classical programming, its machine can solve the problem in 2.5 days. Either way, Google had reached a significant milestone towards realizing the immense promise of quantum computers – “a wonderful achievement” as Knight put it. “It shows that quantum computing is really hard but not impossible,” he added.

However, to do something really useful with quantum computers will require significantly more than 50 qubits. And given that a single qubit will set you back $10,000 or more, quantum computers will become commercially viable only when the cost per qubit has dropped dramatically. What’s more, we’ll have to get round the fact that current qubit devices are super-sensitive to external disturbances, so they have to be enclosed in sealed, cryogenically cooled boxes to maintain their quantum behaviour.

It’s worth recalling that when ENIAC – the first general purpose digital computer – was released in 1945, it could do in 30 seconds what a human could do in 20 hours. But with its vacuum tubes and vast size, ENIAC was as far removed from today’s super-advanced classical devices as today’s quantum computers will be from those in 50 years’ time. That’s why the race is on to scale and deliver a practical quantum computer, with many competing platforms, technologies and companies in the running.

Towards quantum 2.0

Superconducting qubits might ultimately be replaced by something cheaper, more practical and scalable. Proper quantum computers will also require operating systems, programming languages, algorithms, input and output hardware, as well as the all-important storage and memory. That’s why I was particularly pleased to see ORCA – a  UK firm – win one of the IOP’s business awards this year for developing a promising new approach to quantum computing memory, which allows single and entangled photons to be stored and synchronized.

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Inside the quantum bubble

Another key commercial milestone took place in September, when UK firm Cambridge Quantum Computing (CQC) launched the world’s first cloud-based Quantum Random Number Generation (QRNG) service using an IBM quantum computer. CQC offers true maximal randomness or entropy, which is impossible with a classical device and vital for accurate modelling and security applications.

It’s taken us 75 years to get from ENIAC to today’s integrated microprocessors, data centres, cloud-computing derived from “quantum 1.0” devices (semiconductor junctions, lasers and so on). Imagine a world with advanced “quantum 2.0” devices and computers 75 years from now. It’s great to see such a co-ordinated and visionary programme here in the UK right now.

• An industry panel featuring members of the UK quantum-computing sector formed part of the IOP’s recent Quantum2020 conference.