“Quantum things can be in multiple places at the same time,” said Chris Monroe, a University of Maryland physicist who is also the founder of quantum startup IonQ. “The rules are very simple, they’re just confounding.”
Google’s findings, however, are already facing push-back from other industry researchers. A version of Google’s paper leaked online last month and researchers caught a glimpse before it was taken down.
IBM quickly took issue with Google’s claim that it had achieved “quantum supremacy,” a term that refers to a point when a quantum computer can perform a calculation that a traditional computer can’t complete within its lifetime. Google’s leaked paper showed that its quantum processor, Sycamore, finished a calculation in three minutes and 20 seconds – and that it would take the world’s fastest supercomputer 10,000 years to do the same thing.
But IBM researchers say that Google underestimated the conventional supercomputer, called Summit, and said it could actually do the calculation in 2.5 days. Summit was developed by IBM and is located at the Oak Ridge National Laboratory in Tennessee.
Google has not commented on IBM’s claims.
Whether or not Google has achieved “quantum supremacy” or not may matter to competitors, but the semantics could be less important for the field of quantum research. What it does seem to indicate is that the field is maturing.
“The quantum supremacy milestone allegedly achieved by Google is a pivotal step in the quest for practical quantum computers,” John Preskill, a Caltech professor who originally coined the “quantum supremacy” term, wrote in a column after the paper was leaked.
It means quantum computing research can enter a new stage, he wrote, though a significant effect on society “may still be decades away.”
The calculation employed by Google has little practical use, Preskill wrote, other than to test how well the processor works. Monroe echoed that concern.
“The more interesting milestone will be a useful application,” he said.