Magnons Reach 18 Microseconds in Quantum Breakthrough
From Fleeting Ripples To Lasting Signals
For years, anyone trying to build a quantum device around magnetic waves ran into the same wall. The waves vanished almost as soon as they appeared. A few hundred nanoseconds was all you got — far too brief to store a quantum state, let alone pass one along a circuit. Then a Vienna-led experiment changed the picture. A team led by Andrii Chumak at the University of Vienna has now pushed the lifetime of these waves, called magnons, up to 18 microseconds. [1] That is nearly one hundred times longer than any previous result, according to the study published in Science Advances. In practical terms, the signal now survives long enough to be useful.
Magnons are waves of magnetization that travel through magnetic solids, like ripples spreading across a pond after a stone is dropped in. Unlike light, they stay inside the material. That matters because their wavelengths can shrink to just a few nanometers, which means circuits built from them could fit on a chip no bigger than the one already in a smartphone. Magnons also interact naturally with other quasiparticles, including phonons and photons, which makes them attractive for hybrid quantum systems and for quantum metrology — the science of measuring with quantum precision.
The new lifetime figure does more than set a record. It places magnons in the same league as the superconducting qubits used in today’s leading quantum processors. A signal that once disappeared before it could carry anything now approaches the timescales that practical quantum technologies demand. The study was published in Science Advances and involved collaborators at the University of Colorado, Colorado Springs, along with research institutions in Germany, the United States, and Ukraine. [2] The experiments were carried out by Rostyslav Serha during his doctoral research at the University of Vienna.
How Short Wavelengths And Deep Cold Combined
The breakthrough came from combining two separate techniques, each of which addressed a different cause of magnon loss. The first was a change in which magnons the team generated. Conventional experiments used uniform magnons; the Vienna team instead generated short-wavelength magnons. These are naturally less sensitive to tiny defects on the crystal’s surface — defects that had been shortening magnon lifetimes in earlier work. By going to shorter wavelengths, the researchers sidestepped a major source of decay.
The second technique was extreme cooling. The team cooled ultra-pure spheres of yttrium iron garnet, known as YIG, to just 30 millikelvin inside a mixed-phase cryostat — a fraction of a degree above absolute zero. At such temperatures, the thermal processes that normally destroy magnons are effectively frozen out. Heat no longer provides the energy that would otherwise knock the waves apart. Combining the short-wavelength approach with the deep cryogenic environment produced the dramatic extension in lifetime.
The choice of material was not incidental. YIG has long been a standard in magnetism research because of its low magnetic damping, but the Vienna experiment treated purity as a variable rather than a given. The team prepared three YIG spheres with different levels of purity and tested each one. The results followed a clear pattern: the purer the crystal, the longer the magnons survived. Even the least pure sample in the set outperformed every previous experiment on record.
Purity, Not Physics, Sets The Ceiling
The most consequential finding may not be the number itself but where the limit comes from. By comparing the three YIG spheres, the researchers showed that magnon lifetime is not ultimately constrained by a law of physics but by the quality of the material the magnons travel through. That distinction matters enormously. If physics set the ceiling, no amount of engineering could raise it. If the material sets the ceiling, then better manufacturing can.
The practical implication is direct. Future improvements in magnon lifetime depend primarily on advances in materials science — growing cleaner crystals with fewer defects — rather than on discovering an entirely new physical mechanism. As researchers develop even purer magnetic materials, the lifetimes may continue to climb. The path forward is metallurgical and chemical, not theoretical.
With lifetimes reaching 18 microseconds, magnons become more than temporary signals. They could serve as reliable quantum memory devices and as low-loss communication channels that move quantum information across a chip. The researchers say magnons could eventually connect hundreds of qubits through a shared pathway, creating a long-sought “quantum bus” that would help scale future quantum computers. Because magnons interact naturally with many different quantum systems, they could also act as universal translators, letting technologies that normally cannot communicate with one another work together. The finding that purity, not physical law, limits magnon lifetime is the data point that anchors everything else — it tells researchers exactly where to push next.