Don't hold your breath for quantum computers - they can't do everything

London

ANY day now, Google is expected to achieve quantum supremacy - the use of a quantum computer to solve a problem that even the most advanced supercomputer cannot unravel. That milestone, which Google has said that it will reach by year-end, will no doubt be greeted with headlines proclaiming the dawn of the quantum computing age. Prepare for lots of stories about how quantum computing will soon do everything from inventing wonderful new pharmaceuticals and almost-magical new materials (good) to rendering obsolete all existing public-key encryption (not so good).

There is plenty of momentum. Earlier this month, Intel Corp researchers unveiled a superconducting chip for quantum computers. The news follows several other advances in quantum computing over the past two years - from tech big boys such as International Business Machines Corp (IBM) , and Google - which is owned by Alphabet Inc - as well as Canada's D-Wave Systems Inc, the only company to sell a commercial quantum computer (it has sold four) and startups such as Rigetti.