Technical quarrels between the quantum computing experts rarely escape the field's rarefied society. Late Monday, IBM's quantum team chose a very public battle with Google.
In a technical paper and blog post, IBM was aiming for potentially historical scientific results that happened to leak from a collaboration between Google and NASA last month. That draft paper claimed that Google had reached a milestone called "quantum superiority" – a kind of drag race where a quantum computer proves capable of doing something a conventional computer can't.
On Monday, Big Blue's quantum doctorates said Google's claim of quantum superiority was wrong. IBM said Google had essentially rigged the race by not harnessing the full power of modern supercomputers. "This threshold is not met," says IBM's blog post. Google declined to comment.
It will take time for the quantum research community to browse through IBM's claim and any answers from Google. Currently, Jonathan Dowling, a professor at Louisiana State University, says IBM seems to be making some profit. "Google chose a problem they thought was very difficult on a classic machine, but IBM has now demonstrated that the problem is not as hard as Google thought it was," he says.
Whoever is proven right in the end, claims of quantum superiority is largely academic for now. The problem of crushing to show supremacy need not have immediate practical applications. It is a milestone that indicates the field's long-term dream: that quantum computers will unlock new power and profit by enabling advancement in difficult areas such as battery chemistry or health care. IBM has promoted its own quantum exploration program in a different way, highlighting partnerships with quantum curious companies playing with its prototype hardware, such as JP Morgan, which this summer claimed to have figured out how to run financial risk calculations on IBM's quantum hardware .
IBM-Google quantretemps illustrates the paradoxical state of quantum computation. Progress has been made in recent years, and leading companies such as IBM, Google, Intel and Microsoft have built large research teams. Google has claimed for years to be close to demonstrating quantum supremacy, a useful talking point as it competed with rivals to hire top experts and line up supposed customers. While quantum computers appear closer than ever, they remain far from practical use and how far it is not easy to determine.
The Google Draft that appeared online last month described a statistical math problem for both the company's prototype quantum processor, Sycamore, and the world's fastest supercomputer, Summit, at the Oak Ridge National Lab. The task used the results to estimate that a top supercomputer would need about 1
IBM, which developed Summit, says supercomputers could have done it in 2 ½ days, not millennia – and potentially even faster, given more time to finesse implementation. It will still be slower than the time Google's Sycamore quantum chip was posted, but the concept of quantum supremacy as originally thought by Caltech professor John Preskill required the quantum challenger to do something that a classic computer could not do at all.
is not the first time Google's rivals are questioning its quantum superiority plans. In 2017, after the company said it was closing the milestone, IBM researchers released results that appeared to move the pillars. In early 2018, Google unveiled a new quantum chip called Bristlecone that should be ready to demonstrate superiority. Soon, researchers from Chinese e-commerce company Alibaba, which has its own quantum computing program, released analysis claiming that the device could not do what Google said.
Google is expected to publish a peer-reviewed version of the leaked supremacy paper, based on the more recent Sycamore piece, bringing its claim to the scientific reference. IBM's paper released Monday has not yet been peer reviewed, but the company says it will.