John Martinis has already revolutionised quantum computing twice. Now, he is working on another radical rethink of the technology that could deliver machines with unrivalled capabilities ...

Every online bank transfer, private message and Bitcoin transaction rests on the assumption that some math problems are practically impossible to solve. Quantum computers threaten to flip that ...

Quantum computing has long lived in the realm of lab demos and bold PowerPoint slides, but two of the industry’s biggest players now say the first truly useful machines are less than five years away.