What is Quantum Computing? And why does the UK want to lead the world?

As part of his post-Brexit plans, Prime Minister Boris Johnson has announced his intention to see the UK established as the world’s leading quantum computing market. Under his plans to “go big on quantum computing”, Great Britain will secure at least 50% of the market by 2040.

But what is he actually talking about?

What is quantum computing?

First it helps to understand a little about how “classical” computers, like your smartphone or notebook PC, work. Every piece of data processed by the onboard silicon processor is stored in “bits”, a series of ones (1) and zeroes (0). Everything is reduced to very (very) long binary strings – and for most applications, this approach is fine.

Quantum computers take a very different approach. Using the principles of quantum physics, the quantum computer uses a processor called a qubit. The qubit is built around tiny particles like electrons or photons. Unlike the silicon chips used in classical computing, the qubit uses “superposition” to change the internal electrons which can be in several states simultaneously – not just one or zero.

Why does quantum computing matter

By combining several qubits into a quantum computer, it becomes possible to process vast amounts of data very quickly. And every additional qubit doubles the available computing.

The University of Science and Technology of China has already built a computer with 66 qubits. IBM is about to unveil their Eagle quantum processor, containing 127 qubits. Clearly, the race to build the fastest, most powerful computer is already underway.

What can a quantum computer be used for?

Despite these massive technological advances, practical uses remain rare. Writing algorithms to control the qubits is extremely complex, a genuinely specialist skill.

But now the technology exists, computer scientists will be able to develop algorithms that solve major problems. With the ability to crunch vast datasets, they will be better able to understand how a medicine works – and to model the long term effects for instance. They will then be able to detect serious side-effects earlier, creating safer drugs and reducing the riskier field trials required for certification.

Renewable energy, weather mapping, genetic testing, carbon reduction – any application that requires processing lots of information is a candidate for quantum computing in the future.

What about the UK?

The UK does not yet have any working quantum computers – at least none that have been publicly announced. So they are already playing catch-up with other countries who do.

However, a history of pioneering computing breakthroughs – think Alan Turing and his “bombe” that was used to decode wartime Enigma encryption – backed by a world class university system offers some hope. The race is on to build a “quantum advantage” – and Great Britain still has a chance of claiming a significant share of the market.