Quantum Computer

The first complete 'quantum computer'
Ion trap Sustained quantum information processing on a chip
For decades physicists have dreamed of building a quantum computer that could solve certain problems faster than a conventional counterpart. Actually building such a thing has proven extremely difficult, but in August Jonathan Home and colleagues at NIST unveiled the first small-scale device that could be described as a "quantum computer". The chip can perform a complete set of quantum logic operations without significant amounts of information being lost in transit.
Over the past few years, Home's team has used ultracold ions to demonstrate separately all of the steps needed for quantum computation. But in 2009, the group made the crucial breakthrough of combining all these stages on a single device, which was, in our view, such a significant piece of work that we felt compelled to pick it as our "breakthrough of the year".
The device even looks a bit like an early computer chip – but don't expect it to be running a quantum version of Windows any time soon. Its overall accuracy of 94% is impressive for a quantum device, but this must be boosted to 99.99% before it could be used in a large-scale quantum computer comprising many such processors.
What do the quantum computing experts have to say? "A great step forward and most impressive," said Hans Bachor, at the Australian National University. "A tour-de-force," said Boris Blinov of the University of Washington.
Home was back in the news in November, when he teamed up with David Hanneke and others at NIST to create a quantum computer from two trapped ions. The device can perform at least 160 different quantum-computing operations.
Much more work must be done before quantum computers become a commercial reality – but real progress was made in 2009.