Google’s ‘Quantum Supremacy’ Moment May Not Mean What You Think

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 can’t unravel. That milestone, which Google has said 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's 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 like International Business Machines Corp., 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 like Rigetti. Google itself just released software to make it easier for chemists and material scientists to use the quantum machines it and others have built.