QUANTUM COMPUTING

THE THEORY of quantum computing has been understood for a while now. Instead of using traditional transistor gates that can be in one of two states, 1 or 0, a quantum bit or “qubit” can be both at the same time, neither, or any combination. This hugely speeds up processing for certain calculations.

It comes at a cost, though: cooling. One method of building a quantum computer involves superconductors, and they need to be very cold—just above absolute zero. A water block isn’t going to cut it. The cooling system is about the size of a hot water cylinder, even though the processor is less than an inch across. Then there’s the “trapped ion” approach. This uses laser beams to trap and measure ions, which can be induced to carry out calculations thanks to quantum entanglement. This needs less cooling, but the machines can still be very large.

According to one researcher we spoke to on the subject, an interpretation of how quantum computing works is that it makes use of computations across parallel universes. By doing this, it can solve certain problems in maybe just a few hours that even the fastest supercomputer in the world today would take billions of years to calculate.

Which sounds fantastic, but there are, inevitably, some problems. One is the sheer size, which we can expect to come down as the technology matures, and another is that, for the uses that you and your mom have for computers, there’s simply no benefit in using a quantum model. The algorithm being processed needs to be specifically written to take advantage of the processor. So, while you’ll probably never check Facebook, edit video, or play a game on a quantum computer, you may very well interact with an AI running on one. And the technically minded can use a five-qubit quantum computer today at http://quantumexperience.ng.bluemix.net/ qx/experience.