YOU’VE heard of quantum mechanics, now meet the quantum engineers. After decades of being stuck in the lab, quantum science is about to emerge as a technology that will impact your everyday life. If ambitious plans succeed, by 2020 the UK could host the world’s most powerful quantum computer, a secure quantum network spanning the country, and numerous other quantum-powered industries.
This mission kicked off in 2013, when UK chancellor George Osborne announced a £270 million investment in quantum technologies. Researchers are now setting up hubs to focus on particular areas – computing, communications, sensing and imaging – and aim to deliver useful quantum devices within five years, starting in 2015.
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These teams held their first annual meeting, , at the University of Oxford last month to discuss the five-year road map and potential hurdles to overcome – not least the perception that quantum is too weird to be useful.
“Potential hurdles to overcome include the perception that quantum is too weird to be useful”
“When you talk to the general public about quantum physics, the first thing they think about is spooky philosophical things,” of Imperial College London told the meeting. That needs to change. “That’s our critical message: this is now developing technology.”
, who heads the quantum computing hub at Oxford, says the basic science has progressed far enough to make this vision a reality. “It really now needed an engineering push to get us to the next level,” he says.
Unlike an ordinary computer, which runs on binary bits, a quantum computer’s “qubits” can be both a 0 and a 1 at the same time. This feature offers the potential for massive speed boosts when it comes to certain problems like searching databases or machine learning. But while binary bits are based on trusty silicon transistors, the jury is still out on the best approach for building quantum machines.
Walmsley and colleagues are working on a system based on trapped ions, individual charged atoms that are held in place by electromagnetic fields and zapped with lasers to read and write information. It’s called Q20:20, because within two years they plan to build a 20-qubit device, pushing the limits of current quantum computers. By the end of the five-year programme they aim to connect up 20 of these into a 400-qubit processor. “That’s big enough to do a number of things that supercomputers can’t currently do,” says Walmsley.
Qubit network
This modular design takes advantage of recent progress controlling trapped ion qubits in the lab, which showed that it is possible to successfully manipulate these fragile quantum states on a small scale. Now the Oxford group and others have designed a way to network these cells of qubits together into much larger processors. That means swapping one-off lab experiments for precision engineered quantum hardware.
“What’s available in the lab is already of the right performance,” says Walmsley. “If we can show that one of these small-scale things works, then there is no barrier to scaling it up, other than manufacturing more components.”
Since the computer is designed as a network, the qubit cells could potentially be scattered around the country, creating a kind of quantum cloud computer that many people can access – though the initial Q20:20 will probably be confined to a single lab, says Walmsley.
But you won’t have to wait until 2020, as another kind of quantum network is already under construction in the UK and could be available to the public in just two years. , who leads the quantum communications hub at the University of York is building quantum key distribution (QKD) networks over optical fibres around the cities of Bristol and Cambridge, with a plan to link the two across the country via London by the end of the five years.
QKD involves preparing photons in particular quantum states to generate and transmit a cryptographically secure key, which can be used to encrypt data for transmission over a non-quantum channel. Unlike existing cryptography, which relies on hard maths problems and can be cracked with sufficiently powerful computers, QKD is secured by the laws of physics: any attempt to intercept the key will raise the alarm.
Similar networks are already in place in the US and China for use by big business and government, but the UK network will be open to start-ups and even just interested tinkerers. “The idea is once it’s in place, you can let people explore what can be done with it,” says Spiller. “In Bristol the focus is on consumers who like looking at new technology,” he says, while in Cambridge the network will be used by small, high-tech businesses in the area.
Current encryption techniques aren’t yet under threat, but Spiller points out that QKD can ensure security over time. “There are certain sorts of data where people are concerned about the long-term threat of stuff being intercepted now and broken in the future,” he says. “If you’re exposing somebody’s medical records or bank details, you don’t want that to be broken in a number of years’ time.”
Quantum keys are one-use only, so you need to acquire a steady supply of them. of the University of Bristol, and his colleagues are working on a credit-card-sized device that would let people pick up a batch from a point on the network, such as a bank ATM, and use them to log in to various services. “Consumers can access that store of keys and share them with a trusted source such as their bank or mobile phone provider,” says Rarity. You would never need to remember passwords or PINs again – QKD does all the work for you.
“You would never need to remember passwords or PINs again – QKD does all the work for you”
Quantum devices in development at the other UK hubs, like cameras that can see invisible gases or ultra-sensitive gravity detectors that can find pipes underground, have less consumer appeal, but could find wide use in construction and other areas. It might sound mundane, but digging up the wrong roads to fix pipes costs the country millions of pounds, said Knight. The goal is to make the UK a leader in quantum tech, says Rarity. “George Osborne invested because he wanted an industry.”
Other countries are also pouring money into quantum engineering. “This is not unique to the UK,” says of Delft University of Technology in the Netherlands. In July the Dutch government promised €135 million to develop quantum tech over 10 years, and last month computing giant Intel announced a $50 million partnership with Delft to explore how quantum processors could augment the next generation of high-end conventional computers. Meanwhile, in the US, organisations from Google to the Intelligence Advanced Research Projects Activity agency are pouring funds into quantum hardware.
Fundamental science isn’t entirely being left behind as the precision made possible by newly engineered components will let researchers push ever further into the quantum realm, says Hanson, but it’s clear that the shift into applications is under way. “The transition of quantum technology from the lab into the marketplace is an amazing thing to see, given we’ve been thinking about applications since the 1980s,” says Rarity. “It’s only really now that it’s beginning to pay off.”
(Image: Novarc Images/Alamy Stock Photo)
Step by step
1981 Richard Feynman proposes the idea of a quantum computer
1984 Charles Bennett and Gilles Brassard describe a method for quantum key distribution
1985 David Deutsch proves that a universal quantum computer could tackle any problem an ordinary one can solve
1989 First QKD experiment transmits a secret key 32.5 centimetres
1994 Peter Shor invents a quantum algorithm to factor large numbers, the first practical use of a quantum computer
1995 First quantum logic gate built at the US National Institute of Standards and Technology
1998 First algorithm run on a 2-qubit quantum computer at the University of Oxford
2004 First QKD network operational between Harvard University, Boston University and research firm BBN Technologies
2011 D-Wave Systems starts selling what is claims are quantum computers, though this claim is disputed
2012 A quantum computer at University of Bristol, UK, sets a record for factoring numbers with Shor’s algorithm, showing 21 = 3 x 7
This article appeared in print under the headline “Quantum tech to hit the streets”
