It’s hogging so many headlines, you can expect the Hollywood techno-thriller about a top secret quantum computer any day now. But like self-ware robots who want to kill us all, space exploration and flying cars the reality is very different, a long way off and often far more pedestrian than the special effects and flashing lights Hollywood depicts it with.
Any university-level physicist understands the concept of quantum physics and how it can be applied to computing to make mincemeat of today’s largest calculation processes, but it’s all theoretical. The average sci-fi potboiler doesn’t even scratch the surface about robots that can talk to humans in our own language, even though AI and robotics engineers aren’t even completely sure what machines need to navigate the messy and constant cognitive adjustment needed to understand language in real time.
In the same way, a quantum computer is a long way off. Or at least it was, if a Canadian startup called D-Wave Systems can be believed. “The way we build computers now is using the physics of large objects,” says Dr Geordie Rose, founder and chief technology officer of D-Wave Systems. “Classical physics works very well for certain types of problems, so today’s computers are optimal for virtually anything you use a computer for. There’s no way that we know of to build a better computer than the ones we’ve got now that obeys the law of physics.”
Rose calls computers of today ‘awesome tools’ when it comes to the spreadsheets and games we use them for. The reason so many teams and researchers all over the world are pursuing quantum computing is because it presents not just computing power we can only dream of, but power for a totally different kind of computing. Critics of D-Wave’s One have said it’s not even as powerful as a deskbound PC, but the company has been up front that the flagship product isn’t the all-purpose machine from the airport novels. It’s been designed for specific maths calculations and is the basis for bigger and better quantum computing down the track.
So it’s not just about doing what we already do better (Rose describes computers today as ‘very fast adders’). It’s about applying computing to a whole new class of calculation. “I’ve worked in machine learning, which is where you create a framework within which machines learn from experience and get better at some task by being shown examples.
“Consider building machines with human level intelligence or capabilities across a wide range of different fields. We can’t get there with the type of technology we’ve got now and quantum computers are suited to solving some of the problems in that sector. They’ll be things you simply can’t do with the computers we’ve built today no matter how big or fast they go. Intelligent machines are bottlenecked by this problem. The number of instructions you need to solve grows exponentially. It’s the same in speech recognition or natural language processing to extract meaning from text. It’s stuff humans do so well that we have problems making machines do well.”
Rose also talks about the applicability of D-Wave technology to create software for specific purposes, crunching the variables that arise from computer programming processes much better than a human operator. So instead of having to spend millions for a quantum computer, you might benefit from a $0.99 iPad app that was built by one.
Small is beautiful
So how exactly is this possible? Computers grounded in classical physics — from your deskbound PC to your iPad or smartphone — are simple tools that manage millions of tiny objects, each of which occupies one of two states (on or off, 1 or 0), whether it’s power through a transistor, a signal on a magnetic substrate or some other binary device. Put 8 of them together and you have a byte. 1,024 of them and you have kilobyte, and so on.
Quantum computing takes the mind-boggling possibilities that matter doesn’t have to occupy only one state or another. It looks and works like a computer, but the quantum bit (or qubit) on your chip can be on, off, or both at once. Dr Rose explains it’s the critical departure point for the technology. “The devices behave according to the rules of quantum mechanics and not the rules of classical physics. It’s literally impossible for a classical device.”
Most scientists will tell you it’s all high-minded theory, but D-Wave claim they’ve got there, and they’re not the only ones putting their money where their mouth is. In March 2011 the defence and aerospace systems heavyweight Lockheed Martin signed an agreement to buy one of its quantum products.
But D-Wave has made waves in the news for the wrong as well as the right reasons. Many are asking why — if this really is quantum computing — it isn’t front-page news all over the world. The most ambitious academic estimates say we’ll need a decade or more before we finally crack quantum computing. A number of critical voices say D-Wave has great marketing spin rather than a quantum computer.
An article in Spectrum, the journal of the Institute of Electrical and Electronics Engineers, is particularly scathing. It quotes Argonne National Laboratory physicist Paul Benioff (who pioneered quantum computing theory) as saying that even the best prototypes can’t keep more than 10 qubits in entangled states for long because of their inherent instability. “Because of this I am very skeptical of D-Wave’s claims that it has produced a 128-qubit quantum computer,” he said. He also called D-Wave claims of reaching 10,000 qubits ‘advertising hype’.
University of Maryland quantum computing researcher adds that D-Wave hasn’t demonstrated the signatures for quantum entanglement said to be essential in true quantum computing.
Although Rose doesn’t give the impression he believes it, there might even be a conspiracy because of the industry at stake if quantum computing does overturn the chip making field. “Computer architecture has stagnated,” he says. “People in the computer industry don’t like to hear that because they’re saying ‘what about multi-core and what about the chips for mobile phones and what about xyz?’ The bottom line is that all computer chips today are variations on a basic theme and that basic theme has fundamental limitations.”
So with a reported US$65 million worth of investment capital and names like Goldman Sachs, Google and NASA on one side and the physics community on the other, it would seem the jury’s still out for awhile yet. All that’s left to decide in the short term is whether D-Wave is a name to keep in mind.
Everything we know is a lie
At its simplest, quantum mechanics can be described by saying that when you drill right down to the microlevel of matter and energy, nothing behaves the way we see around us. Thermodynamics, gravity and the other laws of force and movement Newton uncovered are ‘classical’ physics that tells us why a ball rolls down a hill, a bubble that’s lighter than air will rise up and the centrifugal force of planets wheeling around the sun counteracts the gravity pulling them in.
But look close enough (on scales our technology is nowhere near revealing) and you’ll see forces that behave as both waves and particles (often at the same time) and particles that exist in more than one places at once, even at opposite ends of the universe, and where anything that happens to one affects the other.
“The laws of classical physics are an illusion,” says D-Wave Systems’ Dr Geordie Rose. “It sits on top of a much more fundamental thing going on under our noses called quantum mechanics. It’s the most fundamental description we have of the way nature actually works. Everything that surrounds us obeys the laws of quantum mechanics and when we filter it through our senses we see a shadow of what’s actually going on. We see things in a certain way but it’s not the way they actually are.
“Now we can start to build technologies that tap into nature at that fundamental level. We’ll have capabilities that are literally impossible for the types of tools we’ve historically built.”
But why is quantum computing such a holy grail? If quantum mechanics and the names associated with it (Heisenberg, Schrodinger) are so disconnected from the reality we see around us every day, what good can it do the rest of us who aren’t theoretical physics PhDs?
Harnessing the power of such esoteric properties of nature and figuring out how to put them to work in our own macro-realm will do nothing short of transform everything you know. Decoupled from traditional laws about cause and effect (an electron must be sent out into a computer circuit to make a calculation, a steel ship weighing thousands of tons must be used to transport minerals), the possibilities for quantum industry are endless.
At the moment the pointy end of quantum research is in the area where we’ve already managed to approach those nanoscales — computer chips.
Size doesn’t matter
The most interesting thing about quantum computing is that it doesn’t mean we have to manufacture at such scales. It’s about the effect quantum mechanics has at our scale of being, not exacting quantum manipulations directly. “You can see these qubits with your naked eye,” Dr Rose says. “They’re loops of metal around a millimetre in circumference. They’re not small.
“It’s commonly understood that quantum mechanics only comes about with small things but it actually applies to all things. And you can make certain materials quite big but still have them behave according to the laws of quantum mechanics. We have a hardware implementation that allows us to build rather large things and make them behave quantum mechanically.”