Sometimes youd be the only person in the world with this new piece of knowledge. Its a pretty wild feeling <\/p>\n
Professor David Reilly<\/p>\n
Its been said that quantum computing will be like going from candlelight to electric light in the way it will transform how we live. Quite a picture, but what exactly is quantum computing?<\/p>\n
For the answer to that question, well have to visit a scale of existence so small that the usual rules of physics are warped, stretched and broken, and there are few layperson terms to lean on. Strap yourself in.<\/p>\n
Luckily, we have a world-leading researcher in quantum computing, Professor David Reilly, to guide us. Most modern technologies are largely based on electromagnetism and Newtonian mechanics, says Reilly in a meeting room at the Universitys Nano Hub. Quantum computing taps into an enormous new area of nano physics that we havent harnessed yet.<\/p>\n
With his youthful looks and laid-back demeanour, Reilly isnt how you might picture a quantum physicist. He has five Fender guitars (with not much time to play them), and a weakness for single malt Scotches. That said, science has never been far below the surface. As a child, he would pull apart flashlights to see how they worked. During his PhD years, knowledge was more important than sleep; he often worked past 3am to finish experiments.<\/p>\n
Sometimes youd be the only person in the world with this new piece of knowledge. Its a pretty wild feeling. A good place to start the quantum computing story is with the humble transistor, which is simply a switch that allows, blocks or varies the flow of electricity, or more correctly, electrons. Invented in 1947, it replaced the large, energy-hungry vacuum tubes in radios and amplifiers, also finding its way into computers.<\/p>\n
This off\/on gate effect of transistors is the origin of the zeroes and ones idea in traditional (aka classical) computers. Ever-shrinking transistors are also how computers have gone from room-filing monsters to tiny devices in our pockets currently, just one square millimetre of computer chip can hold 100 million transistors.<\/p>\n
Incredible, yes, but also unsustainable. With transistors now operating at the size of atoms, they literally cant get much smaller, and theyre now at a scale where the different, nanoscale laws of physics are warping and compromising their usefulness. At that scale, an electron stops behaving like a ball being stopped by the transistor gate, Reilly says. Its more like a wave. It can actually tunnel through or teleport to the other side, so the on\/off effect is lost.<\/p>\n
Quantum computing seeks to solve this problem, but it also promises a great leap forward. Its based on the idea that transistors can be replaced by actual atomic particles where the zeros and ones arent predicated on the flow or non-flow of electrons, but on the property or energy state of the atomic particle itself.<\/p>\n
These particles can come from various sources (and are usually engineered in nanoscale devices) but theyre called collectively, qubits. Now things get trickier. Yes, tricker. Where a transistor can be either one or zero, its a weird fact of quantum physics, that a qubit can be one or zero at the same time, like a spinning coin that holds the possibility of both heads and tails.<\/p>\n
For a single qubit, this doubles the one-andzero mechanism. And for every qubit added, the one\/zero combinations increase exponentially.<\/p>\n
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