A team of physicists in Austria has turned fleeting magnetic waves into long-lasting carriers of quantum information, bringing the possibility of quantum computers the size of a penny significantly closer. The researchers extended the lifespan of these waves, called magnons, from a few hundred nanoseconds to 18 microseconds, an improvement of nearly 100 times.
The magnon problem that held quantum computing back
Magnons are tiny waves of magnetization that move through magnetic solids, similar to ripples spreading across a pond. Unlike photons, which travel through empty space or optical fibers, magnons stay inside magnetic materials. Their wavelengths can shrink to just a few nanometers, meaning circuits built from them could fit onto chips no larger than those already found in smartphones.
For years, the biggest obstacle was their extremely short lifetime. Magnons survived for only a few hundred nanoseconds, disappearing too quickly to reliably store or transfer quantum information. The new study, led by Andrii Chumak at the University of Vienna and published in Science Advances, changes that picture entirely.
How researchers made magnons last nearly 100 times longer
The breakthrough came from combining two techniques. First, instead of using conventional uniform magnons, the team generated short-wavelength magnons. These are naturally less sensitive to tiny defects on the crystal's surface, which had shortened magnon lifetimes in previous experiments. Second, the researchers refined the material itself.
They discovered that the main limitation on magnon lifetime is not a fundamental law of physics, but the purity of the material through which the magnons travel. This means future improvements could come from better manufacturing rather than entirely new discoveries.
With lifetimes now reaching 18 microseconds, magnons approach the timescales needed for practical quantum technologies. Their performance now compares to the superconducting qubits used in today's leading quantum processors. Magnons also interact naturally with other fundamental quasiparticles, including phonons and photons, making them attractive building blocks for hybrid quantum systems and quantum metrology.
The advance could eventually help make ultra-compact quantum computers, potentially as small as a 1-cent coin. For local researchers and the broader physics community in Austria, the finding reframes the challenge ahead: the path to smaller quantum computers now depends more on materials engineering than on rewriting the rules of physics.
