Quantum computers move closer to reality

Scientists developing the world's fastest, most powerful computers have moved closer to creating a practical prototype after they found a way to shield the gen-next quantum computers from harmful external noise.
Scientists have been looking at how they can harness microwaves, already used in smartphone technology, so that atomic particles can be used to store and process data on a new type of computer called a quantum computer.
The ability to store and process huge amounts of data in a quantum way (on an atomic scale) would revolutionise computing, making it possible to carry out massive calculations and enabling computers to understand chemical reactions, create new medicines and carry out seemingly impossible simulations, such as the creation of our universe.

To build a quantum computer, scientists trap electrically charged atoms (ions) and control them so that they can be harnessed to form the "atomic highways" that would build the computer network.
The first small-scale ion trap quantum computers have already been built using lasers to carry out calculations within the 'quantum processor', but the number of lasers needed to make a large-scale quantum computer would make this a substantial engineering challenge.
A new generation of quantum computers is now being devised utilising microwaves instead, which are easier to use and which should bring the construction of a large-scale ion-trap quantum-information processor much closer.

However, the quantum effects that give a quantum computer its tremendous power (such as quantum superposition, where a single object can be at two different places simultaneously) are easily destroyed by any external noise.

Now, Dr Winfried Hensinger, along with postdoctoral fellow Simon Webster and PhD students Seb Weidt, Kim Lake and James McLoughlin, who form part of Ion Quantum Technology Group at the University of Sussex, have come up with an easy way to shield the quantum computer from external noise.
It would enable large-scale operation of a microwave quantum computer.
By applying a special combination of microwaves and radio frequency fields, the team were able to modify the atoms so that they became more resilient to external noise.

"While large scale quantum computers might be still 10-30 years away, we have now managed to clear another big hurdle and we are highly excited about the opportunities that arise from this discovery," Hensinger said.
The paper is published in the journal Physical Review Letters.