Governments around the world are taking a leap into the future by investing heavily in quantum technology research. The UK alone has pledged £270m over five years, with the more cautious Australian government promising a AU$25m (£15m) investment over the same period, and the Canadians putting in $50m (£31m).

So just what are they investing in, and why? While the end product may be some way off, quantum technologies promise to deliver multibillion-pound industries across multiple sectors in return for that investment.

Quantum has touched a political nerve, from the UK’s National Quantum Technologies Programme, Australia’s Centre for Quantum Computation and Communication Technology or the European Union’s €1bn (£0.9bn) for an EU quantum manifesto, not to mention Canadian prime minister Justin Trudeau’s well-documented knowledge of the topic.

What is quantum technology?

When you think of quantum you’re transported into the subatomic world of Schrödinger and his cat and the ability to be in two states at the same time.

In the case of the cat, locked in a box with a randomly triggered radiation source, it’s both alive and dead until the box is opened and it can be observed as either one or the other.

In the quantum computing world, the bits at the heart of a computer with a binary state of either one or zero become qubits (quantum bits), which can simultaneously be a one, zero, both or anything in-between. If a binary system has a one or zero at opposite poles of a sphere, then a quantum one has values anywhere and everywhere.

This makes a quantum system fast at calculating because it can test every possibility simultaneously; no waiting for one calculation after another. Interrupt it at any given time to collapse it at one of its states, and hey presto you have your answer.

There is, of course, a caveat: you have to control the qubits and the subatomic particles in which they are stored. And that is very, very hard indeed. Even the likes of Intel, which last year pledged $50m (£39m) to quantum computing research at the University of Delft, admit that a practical quantum computer is at least a decade away.

Privacy is dead

What can we look forward to when quantum computers do arrive? Well, there’s the death of encryption for a start.

Encryption of data relies upon how time consuming it is to factor very large numbers into two primes. A quantum computer will quickly decrypt data that would take billions of years today. You might think this bad from the security perspective, allowing criminals to decrypt every encrypted database.

But quantum research is expensive, very expensive. So the “good guys”, with the government budgets, will get the tech first, by a long margin. And when the bad guys do get all the gear, what quantum giveth it will soon taketh away again. While quantum computers will crack most any encryption, you’ll know your data’s been looked at, thanks to something called entanglement. Einstein called this “spooky action at a distance” and spooky it may be, but it does provide us with perfect privacy. Quantum key distribution systems are already being developed that will know if they are being eavesdropped on and stop communicating until the spy goes away.

What will governments do with quantum?

Can quantum help governments wage war? Perhaps. The Ministry of Defence lab at Porton Down has been developing a device to measure tiny fluctuations in gravitational pull, which would act like super accurate radar, with the capability to see through walls or deep underground.

But some of the most exciting possibilities lie in the area of public health. Researchers at the University of Glasgow, working for one of the quantum technology hubs, established through £120m of UK investment, are hoping to revolutionise quantum imaging. Their projects include developing ultrasensitive cameras that can actually detect light down to a single photon. This has the potential to detect cancer without invasive medical imaging.

And Australian researchers from the government-funded Centre for Quantum Computation and Communication Technology are taking the field of medical imaging into a whole new dimension. Rather than using magnets to create 3D images, the team’s nano-MRI project uses the natural magnetic properties of the qubit to, in theory at least, allow imaging at the molecular level. If used to determine the structure of biomolecules such as proteins it could overcome many issues researchers face when developing new drugs.

At the moment quantum computing is largely speculative and hugely expensive. It has staggering potential, but it remains to be seen whether governments’ investments will pay off in the real world of public services.

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