Quantum Computers Could Solve Countless Problems--And Create a Lot of New Ones

One of the secrets to building the world's most powerful computer is probably perched by your bathroom sink. At IBM's Thomas J. Watson Research Center in New York State's Westchester County, scientists always keep a box of dental floss--Reach is the preferred brand--close by in case they need to tinker with their oil-drum-size quantum computers, the latest of which can complete certain tasks millions of times as fast as your laptop. Inside the shimmering aluminum canister of IBM's System One, which sits shielded by the same kind of protective glass as the Mona Lisa, are three cylinders of diminishing circumference, rather like a set of Russian dolls. To work properly, this chip requires super-cooling to 0.015 kelvins--a smidgen above absolute zero and colder than outer space. Most materials contract or grow brittle and snap under such intense chill.