SANTA BARBARA, Calif. — Google said on Wednesday that it had achieved a long-sought breakthrough called “quantum supremacy,” which could allow new kinds of computers to do calculations at speeds that are inconceivable with today’s technology.

The Silicon Valley giant’s research lab in Santa Barbara, Calif., reached a milestone that scientists had been working toward since the 1980s: Its quantum computer performed a task that isn’t possible with traditional computers, according to a paper published in the science journal Nature.

A quantum machine could one day drive big advances in areas like artificial intelligence and make even the most powerful supercomputers look like toys. The Google device did in 3 minutes 20 seconds a mathematical calculation that supercomputers could not complete in under 10,000 years, the company said in its paper.

Scientists likened Google’s announcement to the Wright brothers’ first plane flight in 1903 — proof that something is really possible even though it may be years before it can fulfill its potential.