The potential power of quantum computing is difficult to comprehend, but its impact is likely to be game changing in science, business and government.
The subatomic quantum world is a magical place in which things can be both particles and waves at the same time, where every possibility exists until we look at it and where uncertainty is king. But scientists are increasingly harnessing the slippery properties of this realm to build computers so powerful they make the fastest supercomputer look like a ZX Spectrum.
Traditional computers have revolutionised the world with the deceptively simple use of bits – binary units of information that can be either a 0 or a 1. By combining these 0s and 1s into long chains of commands, programmes can be created which send rockets to Mars, fly aeroplanes and dredge through vast libraries of information in less than a second.
But ever since the early 80s, when classical computing was itself still going mainstream, physicists were speculating about the possibilities of using quantum properties to build computers with bits other than just 0 or 1. These quantum bits or ‘qubits’ could not only be 0 or 1 but both at the same time. Qubits are particles like electrons, photons or single atoms – entities small enough to exist on the quantum scale and hence take advantage of the quantum property of ‘superposition’ – essentially being in two states at the same time. While classical computers can only perform one operation at a time, superposition of states allows quantum computers to perform potentially millions of calculations in the same moment.
“You could have a whole array of qubits, like 1,000 of them,” says professor David Lucas, head of the Ion Trap Quantum Computing team at Oxford University. “That memory register can store something like 21,000 numbers simultaneously. To do that in a traditional computer would require more bits than there are atoms in the known universe.”
This kind of computational power could have massive implications. Its presence could be particularly felt in the likes of trawling through huge sets of data, solving complicated logistical problems and in areas such as cryptography where complex computations are used to protect the security of private communications like bank transactions.
Unfortunately quantum computing isn’t quite there yet. The number of qubits being successfully manipulated is fewer than 20 – not enough to solve computations faster than classical computers already do. This isn’t for want of trying however. Currently, teams from Oxford to Austria and from Australia to the US are working on making quantum computers.
At Oxford, Professor Lucas’ team is working on the ion trap method, a system making breakthroughs in the accuracy of quantum computations. “You need very precise operations,” says Lucas. “Putting information into these qubits and getting it out again all needs to be done with a precision of something like 99.9 per cent. What we’re very excited about here at Oxford is that for the first time we’ve done all the basic operations necessary to manipulate these qubits with this 99.9 per cent precision just within the last year.”
The snag is that the team can only achieve this accuracy using just one or two qubits. Elsewhere, teams are working with less accuracy but more qubits. The record so far, according to Lucas, is held by a team in Innsbruck in Austria, which has managed to manipulate 14 qubits.
That was until a small Canadian start up called D-Wave stepped in. D-Wave claimed they had solved a computation with more than 14 qubits. And they weren’t just claiming a couple more, or ten more, or even 100 more qubits. Those at D-Wave were claiming to use 1,000 more qubits.
Standing taller than a human and clad all in black, the imposing D-Wave 2X computer looks like it might turn sentient at any moment and go quickly about the business of taking over the world. “Quantum computing is going to move business, science, and government forward in unprecedented ways,” says Murray Thom, D-Waves’ director of professional services. “It’s all a matter of solving problems that are too complex for today’s computational systems. This innovation could lead to the exploration of new and cleaner sources of energy, superior image recognition, more accurate financial forecasting and precise genome mapping.”
There are a few issues though, the most serious being that most scientists don’t believe the D-Wave is really a quantum computer. Tests carried out by Matthias Troyer, a computer scientist at the Institute for Theoretical Physics in Zurich, found that D-Wave didn’t perform faster than classical computers over a range of specific computations. But D-Wave claims the slow performance was caused by calibration errors in the test. In any case, the scepticism of the scientific community hasn’t stopped big organisations taking on the D-Wave technology. NASA has bought a machine, as has Google, and Lockheed Martin is using a D-Wave computer to test its flight control systems.
Professor Lucas remains sceptical but he does predict that advances in quantum computing will accelerate in the near future, especially with the funding it’s currently receiving (the UK government alone has pledged £270 million over the next five years). “It looks like at the moment the only limitation is technical barriers,” says Lucas, “and how fast you get through a technical barrier often depends on how many resources you throw at it.”
So does he see a fully functioning quantum computer coming so? “It’s not going to happen in 10 years,” he says, “but I’ll be surprised if it hasn’t happened in 50”.
|The perks of another dimension|
|D-Wave’s Murray Thom on real-world applications of quantum computersSELF-DRIVING CARSSelf-driving cars are complex, and the engineering involves a fair bit of machine learning. This allows them to automatically process large data streams while maintaining stable control in a real environment. Training and operating this software often involves optimising mathematical models like neural networks. D-Wave systems can be thought of as human-made neural networks that use quantum mechanics.SAFER AEROPLANES
A big issue in the flight industry is certifying that the control software is thoroughly tested; it’s an exhaustive and time-consuming process. These are incredibly complex systems and testing and validating the software is one of the biggest expenses of a new aircraft project. Lockheed has been using a D-Wave system to find faster, better ways to make safer airplanes more efficiently.
MORE EFFECTIVE DRUGS
Understanding the behaviour of proteins is a key factor in drug development. Simulating the folding of proteins effectively could significantly enhance our understanding of complex biological systems and our ability to design powerful new drugs. Quantum computing may have a unique ability to explore the multitudes of possible folding configurations of these interesting molecules, leading to a deeper understanding of the best pharmaceutical solutions.”
FINDING NEW PLANETS
One application where quantum computers could make a contribution is the Kepler search for habitable planets. It’s a big search and data analysis problem, one where a quantum computer could be better at classifying observed characteristics that a classical algorithm would overlook.
There are many applications for quantum computing in terms of space exploration and logistics, healthcare and finance. Any problem where individuals are trying to find the optimal solution of many discrete variables could be a good application for D- Wave systems.
More by Lee Williams:
PLEASE SHARE YOUR EXPERIENCES AND VIEWS IN THE COMMENT SECTION
Photo credit: Patrick Dep from Flickr