Scientists have made a major breakthrough that could bring ultra-compact quantum computers closer to reality by turning tiny magnetic waves, known as magnons, into longer-lasting carriers of quantum information.
The international research team, led by physicist Andrii Chumak of the University of Vienna, increased the lifetime of magnons from just a few hundred nanoseconds to as long as 18 microseconds. This is nearly 100 times longer than what had previously been achieved.
The discovery could open the door to future quantum technologies that are much smaller than todayโs systems, possibly even quantum computers about the size of a 1-cent coin.
Magnons are tiny waves of magnetization that move through magnetic materials. They are similar to ripples spreading across water after a stone is dropped into a pond. However, unlike photons, which can travel through empty space or optical fibres, magnons remain inside magnetic solids.
One reason magnons are so promising is their extremely small wavelength. Their wavelengths can be only a few nanometres long, which means magnon-based circuits could be built on very small chips. This could allow future quantum devices to become much more compact than many current systems.
Magnons are also attractive because they naturally interact with other quantum systems, including photons and phonons. This makes them useful for building hybrid quantum technologies, where different quantum components need to communicate with one another.
For many years, however, magnons had one major weakness: they disappeared too quickly. Their short lifetime made it difficult to use them for storing or transferring quantum information. If quantum information cannot last long enough, it becomes unreliable for practical computing.
The new study has changed that picture. By extending magnon lifetimes up to 18 microseconds, the researchers showed that magnons can survive long enough to become useful in quantum technology. Their lifetime is now approaching the timescale needed for practical use and is comparable to some superconducting qubits used in leading quantum processors.
The team achieved the breakthrough by combining two important approaches. First, they used short-wavelength magnons instead of conventional uniform magnons. These short-wavelength magnons are less affected by tiny defects on the surface of the crystal, which had previously reduced magnon lifetimes.
Second, the researchers cooled ultra-pure spheres of yttrium iron garnet, known as YIG, to only 30 millikelvin. This temperature is extremely close to absolute zero. At such low temperatures, many thermal processes that normally destroy magnons are almost completely frozen out.
One of the most important findings of the study is that the lifetime of magnons is not mainly limited by an unavoidable law of physics. Instead, the researchers found that the biggest limitation comes from the purity of the material itself.
By testing three YIG spheres with different levels of purity, the scientists discovered that purer crystals allowed magnons to survive for longer periods. Even the least pure sample used in the experiment performed better than previous results.
This means that future progress may depend strongly on better material production. If scientists can create even purer magnetic materials, magnon lifetimes may continue to improve.
The discovery is important for quantum computing because long-lived magnons could serve as quantum memory devices or as low-loss channels for moving quantum information across a chip. They could also act as a โquantum bus,โ helping connect many qubits inside future quantum computers.
Because magnons can interact with different quantum systems, they may also serve as translators between technologies that normally do not communicate easily. This could help researchers build more flexible and scalable quantum devices.
The study was carried out by researchers from the University of Vienna, the University of Colorado Colorado Springs, and other institutions in Germany, the United States, and Ukraine. The work was based on experiments conducted by Rostyslav Serha during his doctoral research.
This breakthrough suggests that magnons, once seen as too short-lived for practical use, may become key building blocks in the next generation of quantum computers and quantum communication systems.
Reference
Serha, R. O., McAllister, K. H., Majcen, F., Knauer, S., Reimann, T., Dubs, C., Melkov, G. A., Serga, A. A., Tyberkevych, V. S., Chumak, A. V., & Bozhko, D. A. (2026). Ultralong-living magnons in the quantum limit. Science Advances, 12(18). https://doi.org/10.1126/sciadv.aee2344