THE MOST INTERESTING MACHINE IN THE WORLD
Quantum computing—magnificent in conception though embryonic in performance—is being touted as the next great information-technology revolution.
Enthusiasts are predicting that quantum machines will solve problems beyond the reach of conventional computers, transforming everything from medical research to the concepts of space and time.
Meanwhile, the actual quantum computers being tested in university and corporate laboratories are mostly exotic divas that run at temperatures colder than intergalactic space and crash in milliseconds if intruded on by the outside world.
“I worry a lot about the hype,” John Preskill told me recently as we chatted in his office in the gleaming, glass-shrouded building at the California Institute of Technology in Pasadena where his Institute for Quantum Information does its weird work. A long-sighted physicist in the tradition of Caltech’s Richard Feynman, Preskill is a leading advocate of quantum computing. But even he pooh-poohs the idea that quantum computers will soon replace our laptops.
“Everybody believes it, but nobody can prove it,” he said. “Changing everything in 10 years is not realistic.”
Such reservations haven’t kept governments and the private sector from betting that visionaries like Preskill—and like China’s $11 billion in developing quantum computers and quantum-ready networks. The U.S. government and the European Union are in for more than a billion dollars each. IBM has put a rudimentary quantum computer online, complete with tutorials on how to frame questions it can understand. (Sample instruction: “Apply a Hadamard gate to q[0] by dragging and dropping the H gate onto the q[0] line.”) Amazon’s cloud-computing services now include access to quantum computers operated by IonQ, D-Wave Systems, and the Berkeley chipmaker Rigetti Computing. Google claims to have attained “quantum supremacy,” a term Preskill coined for the ability to solve problems no conventional computer can handle.
