Canadian Company Claims Quantum Supremacy, but Academics Disagree

D-Wave claims to have achieved ‘quantum supremacy’. As with any major breakthrough in quantum computing, there are several academics who dispute the claim.

The Canadian-American quantum company D-Wave is claiming the title of ‘quantum supremacy’: the holy grail for quantum computers. In a paper published in the academic journal Science, D-Wave describes how it has been able to solve a problem that would never be possible with a traditional supercomputer. “This is what everyone in the industry is striving for, and we’re the first to actually do it,” says a proud CEO Alan Baratz to the Wall Street Journal.

The specific problem that D-Wave’s quantum computer has managed to solve relates to the simulation of materials with a complex magnetic field at an extremely high level of detail. D-Wave was able to complete this task in twenty minutes using a quantum computer, while a classical computer would need a million years to do the same.

According to D-Wave, this is the first time a quantum computer has demonstrated superiority over traditional computers in a practical situation. The ability to simulate new magnetic materials could be applicable in multiple industries. D-Wave prefers to speak of ‘quantum advantage’ rather than ‘supremacy’, but it still proclaims the latter as well.

This is what everyone in the industry is striving for, and we’re the first to actually do it.

Alan Baratz, CEO D-Wave (via Wall Street Journal)

Criticism from Academics

Academics question D-Wave’s claim. Several scientists say that the problem D-Wave describes does not require quantum computers at all. Dries Sels, a Belgian computer scientist from New York University, claims that by using tensor networks, he was able to perform similar calculations to D-Wave on an ordinary laptop in just two hours.

Swiss scientists from the University of Lausanne tried to solve the exact same problem with a regular computer. It took them four days, which is much faster than the one million years that D-Wave claimed would be necessary. The Canadian company refutes the criticism and says they find no evidence in it that disproves their claim of quantum supremacy. “They didn’t do all the problems, sizes, observations, and all the simulation tests that we did,” D-Wave defends itself.

D-Wave is not the first company to claim quantum supremacy. Google claimed the major breakthrough in 2019, which was also disputed at the time. Chinese scientists dethroned Google three years later. Whether D-Wave’s claim will stand remains to be seen.

Error Burden

The quest for quantum supremacy is not the biggest problem that computer science is grappling with. The way qubits behave compared to classical binary units allows for much more complex calculations, but also introduces a higher error burden. Techniques to reduce this error burden have so far proven to be expensive and/or poorly scalable.

Here too, we have possibly seen major breakthroughs recently. Microsoft and AWS introduced quantum chips that can apply error correction much more efficiently at the processor level. The first practically deployable quantum computers are still waiting to be realized, but they seem to be no longer a distant dream.