Researchers at the University of Oxford have made an important breakthrough in the quest to build a quantum computer capable of processing huge amounts of information all at once.

They achieved a quantum logic gate with record-breaking 99.9% precision, reaching the benchmark required theoretically to build a quantum computer. The computers, which function according to the laws of quantum physics, would far outstrip the processing power of today’s computers.

The team achieved the logic gate, which places two atoms in a state of quantum entanglement and is the fundamental building block of quantum computing, with a precision (or fidelity) substantially greater than the previous world record. Quantum entanglement – a phenomenon described by Einstein as ‘spooky’ but which is at the heart of quantum technologies – occurs when two particles stay connected, such that an action on one affects the other, even when they are separated by great distances.

Dr Chris Ballance, a research fellow at Magdalen College, Oxford and lead author of the paper, said: ‘The development of a “quantum computer” is one of the outstanding technological challenges of the 21st century. A quantum computer is a machine that processes information according to the rules of quantum physics, which govern the behaviour of microscopic particles at the scale of atoms and smaller.”

“An important point is that it is not merely a different technology for computing in the same way our everyday computers work; it is at a very fundamental level a different way of processing information. It turns out that this quantum-mechanical way of manipulating information gives quantum computers the ability to solve certain problems far more efficiently than any conceivable conventional computer. One such problem is related to breaking secure codes, while another is searching large data sets. Quantum computers are naturally well-suited to simulating other quantum systems, which may help, for example, our understanding of complex molecules relevant to chemistry and biology.”

The research, carried out by scientists from the Engineering and Physical Sciences Research Council (EPSRC)-funded Networked Quantum Information Technologies Hub (NQIT), which is led by Oxford University, is reported in the journal Physical Review Letters.