An ordinary laptop solved a problem thought to require a quantum computer A personal laptop helped solve a quantum physics problem once claimed to be beyond the reach of classical computers. - Date: - July 20, 2026 - Source: - Simons Foundation - Summary: - A quantum problem once described as impossible for classical computers has now been solved using relatively modest hardware. Researchers used tensor networks to compress the overwhelming wave function created by hundreds of entangled qubits, allowing some calculations to run on a laptop.

Their results matched both theoretical predictions and simulations performed with a quantum computer. The method could open new paths for exploring quantum dynamics and materials. - Share: Physicists have used an ordinary computer, advanced mathematics, and specialized software to solve a difficult quantum physics problem that had been described as beyond the reach of classical machines.

The work was carried out by researchers at the Center for Computational Quantum Physics (CCQ) at the Simons Foundation's Flatiron Institute, together with collaborators at Boston University. Their method proved efficient enough for some of the calculations to run on a personal laptop. By extracting more computing power from conventional hardware, the approach could expand the range of quantum dynamics problems scientists can study.

It may also offer a useful strategy for optimization problems in which researchers must identify the best answer among many possible solutions. The findings were published in the journal Science. Simulating Hundreds of Interacting Qubits The challenge involved modeling hundreds of interacting 'qubits,' the quantum counterparts of the bits used by traditional computers.

The qubits were arranged in square, cubic, or diamond shaped lattices. A conventional bit stores either a 0 or a 1. A qubit, however, can exist in a superposition of multiple states.

This feature gives quantum systems their unusual capabilities, but it also makes their behavior extremely difficult to reproduce on a classical computer. In a March 2025 article, also published in Science, another research team reported using a quantum computer to calculate the dynamics of an especially complex qubit system. That team argued that a classical computer could not match the achievement.

"Whenever we [at the CCQ] see these kinds of claims, we're always a bit skeptical," says Joseph Tindall, an associate research scientist at the CCQ and first author on the new Science paper. "Like, 'Did you try this? Did you try that?'" For the CCQ researchers, the claim offered a compelling way to test the limits of their own techniques.

The problem served as an opportunity to take their tools "out for a test drive," says study co-author and CCQ research scientist Miles Stoudenmire. "We could have picked some more arbitrary target," Stoudenmire says. "But it was like 'Why not pick this one that has a big claim attached to it?'" The Challenge of Quantum Entanglement One of the greatest obstacles was quantum entanglement.

When qubits become entangled, their properties remain connected, even when the qubits are separated by large distances.