(TechnologyReview) MIT’s Gordon Lichfield goes inside the race between IBM and Google to build the best quantum computer on earth in an extensive article that examines both the technology and culture of the two organizations.
IBM’s objection to Google’s announcement of quantum supremacy was not that Google’s experiment was less successful than claimed, but that it was a meaningless test in the first place. Unlike most of the quantum computing world, IBM doesn’t think “quantum supremacy” is the technology’s Wright brothers moment; in fact, it doesn’t even believe there will be such a moment.
IBM is instead chasing a very different measure of success, something it calls “quantum advantage.” This isn’t a mere difference of words or even of science, but a philosophical stance with roots in IBM’s history, culture, and ambitions—and, perhaps, the fact that for eight years its revenue and profit have been in almost unremitting decline, while Google and its parent company Alphabet have only seen their numbers grow. This context, and these differing goals, could influence which—if either—comes out ahead in the quantum computing race.
IBM believes the fastest route to its so-called quantum advantage is a future in which quantum computers won’t necessarily leave classical ones in the dust but will do some useful things somewhat faster or more efficiently—enough to make them economically worthwhile. Whereas quantum supremacy is a single milestone, quantum advantage is a “continuum,” the IBMers say—a gradually expanding world of possibility.
IBM sees Google’s quantum supremacy demonstration as “a parlor trick,” says Scott Aaronson, a physicist at the University of Texas at Austin, who contributed to the quantum algorithms Google is using.
Google, of course, sees it rather differently. Lacking IBM’s quantum expertise, Google hired a team from outside, led by John Martinis, a physicist at the University of California, Santa Barbara. Martinis and his group were already among the world’s best quantum computer makers—they had managed to string up to nine qubits together.
Regardless of whether you agree with Google’s position or IBM’s, the next goal is clear: to build a quantum computer that can do something useful. The hope is that such machines could one day solve problems that require unfeasible amounts of brute-force computing power now, like modeling complex molecules to help discover new drugs and materials, or optimizing city traffic flows in real time to reduce congestion, or making longer-term weather predictions.