March 11, 20253 min readControversial Quantum Advantage Claim Made by Computing Firm D-WaveThe company says it has solved the first problem of scientific relevance with a quantum processor faster than could be done with classical computersbut others disagreeBy Davide Castelvecchi & Nature magazine D-Waves Advantage2 quantum processor. D-Wave Quantum Inc.A quantum processor has solved a physics problem on the behaviour of magnetism in certain solids that would take hundreds of thousands of years to calculate on the largest conventional supercomputers. The result is the latest claim of machine showing quantum advantage over classical computers.Although Google and others have claimed to achieve quantum advantage most lately with the Sycamore chip that Google unveiled in December researchers at D-Wave, a company in Burnaby, Canada, say that their result, published in Science, is the first that solves an actual physics question. We believe its the first time anyone has done it on a problem of scientific interest, says D-Wave physicist Andrew King.The D-Wave team did great work but classical computing should not be counted out quite yet, says Miles Stoudenmire, a researcher at the Flatiron Institute Center for Computational Quantum Physics in New York City. We're still in the race.On supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.The result also validates the approach the company has taken to quantum computing, King says. Rather than building a universal quantum computer one that could run any quantum algorithm D-Wave has focused on an approach that was limited to performing certain calculations, but easier to scale.An early pioneer in the quantum field, D-Wave machines have long led the industry in terms of number of qubits, the quantum equivalent of classical bits of information. The latest processor has thousands of qubits. These are results of 25 years of hardware development and research at D-Wave, says Mohammad Amin, another senior physicist at the company.Magnetic problemThe problem solved by D-Wave concerns the theory of magnetism, a large field of theoretical physics. The electron spins of each atom act like magnetic needles, and the way they orient themselves inside a solid in response to their neighbours orientations has long provided a prototype for the study of complex systems.In a typical permanent magnet, the spins all align in the same direction. But in general materials, neighbouring spins give conflicting influences on each other, and stable arrangements either dont exist or are extremely difficult to predict. Quantum effects add complications.King, Amin and their collaborators at D-Wave and at several academic labs used the latest D-Wave machine, called Advantage2, to simulate the arrangements of spins in several 3D crystal structures. They studied a specific problem in which the temperature of the material starts at absolute zero, and quantum fluctuations let it transition from one state to another. They estimate that their machine achieved the result exponentially faster than any classical calculation.Advantage claims challengedThe result follows several claims of quantum advantage. Google made the first claim of a quantum advantage in a paper that caused a sensation in 2019. It used a fully programmable, or universal, quantum computer with superconducting qubits to perform a calculation that was designed to test for quantum advantage but had no practical application. Soon, IBM and other companies showed that by improving classical techniques, they could still run the same calculations on ordinary computers.IBM then achieved a quantum advantage on a useful application in 2023. But that claim suffered a similar fate to Googles last year when computational physicist Miles Stoudenmire, at the Flatiron Institute Center for Computational Quantum Physics in New York City, and his collaborators showed their classical algorithms could solve the problem as quickly.Last week, in response to a preprint version of the D-Wave paper, Stoudenmire posted a result on the arXiv in which his team improved on classical algorithms to do some of the same calculations as the D-Wave machine.Its an excellent piece of research, and a great scientific breakthrough as well, says Juan Carrasquilla, a computational physicist at ETH Zurich and a co-author of the D-Wave paper. (A separate team also posted a challenge to some of D-Waves claims just this week.) Still, the D-Wave stood well in front of the spoofing from conventional computers, he says.What they did, is a subset of what we did, says King. They advanced the classical state of the art, but not as far as our results.Stoudenmire's team is improving its techniques to cover all of the D-Wave simulations. Were trying now, he says. We believe it will work. More generally, Stoudenmire says, it is often not appreciated how quickly classical computing techniques are improving.This article is reproduced with permission and was first published on March 12, 2025.