Scientists solve difficult quantum problem using ordinary computers Scientists used tensor networks and classical computers to solve a quantum problem once thought impossible without quantum machines. Edited By: Joseph Shavit Quantum computing’s edge looked closer after a hard physics problem seemed beyond classical machines. But a new result shows compressed math and smarter algorithms can match or beat that benchmark, raising fresh questions about where true quantum advantage really begins. For years, quantum computers have carried a bold promise. They could solve problems so complex that even the world’s best classical computers would fail. That promise fueled a global race among scientists and technology companies to prove “quantum advantage,” the point where quantum machines outperform traditional computing systems. Now, physicists at the Center for Computational Quantum Physics at the Simons Foundation’s Flatiron Institute and collaborators at Boston University have shaken that narrative. Using advanced mathematics, tensor networks and clever coding, the team solved a difficult quantum physics problem that another group had claimed only a quantum computer could handle. The breakthrough shows that classical computers may still have far more power than many researchers expected. In fact, some of the calculations were completed on a personal laptop. “Whenever we see these kinds of claims, we’re always a bit skeptical,” said Joseph Tindall, associate research scientist at the Center for Computational Quantum Physics and first author of the study. “Like, ‘Did you try this? Did you try that?’” The work challenges growing assumptions about the limits of conventional computing. It also opens new paths for studying quantum materials, optimization problems and the strange behavior of entangled particles. A Fight Over Quantum Advantage The story began earlier this year when another research team reported that a quantum computer had simulated a highly complicated system of interacting qubits. The researchers argued that classical