Is it magic? Physicists at the University of Konstanz have successfully altered the properties of a material using light and magnons in a non-thermal manner.
What if it were possible to temporarily change a material so completely that it behaves like an entirely different one? No special chemicals, extreme temperatures, or advanced machinery are needed—just light. By shining precise pulses of light onto a material, scientists can trigger magnetic activity within it. These interactions create coordinated magnetic vibrations, known as magnons, that can carry and store information at incredibly high (terahertz) frequencies.
Even more remarkably, this light-based technique operates at room temperature and does not generate substantial heat. It also works without relying on rare or costly elements, instead using common, naturally occurring crystals. As if that weren’t enough, the same method could also allow researchers to explore delicate quantum effects, phenomena typically observed only at temperatures near -270 degrees Celsius, all without any need for deep freezing or cryogenic systems.
As unlikely as it may seem, this breakthrough is real. Developed by a team of physicists at the University of Konstanz under the leadership of Davide Bossini, the method involves using laser pulses to excite magnon pairs in a controlled, coherent manner. This approach has led to surprising and promising results, not only for improving information technologies but also for advancing quantum research. Their findings were published in Science Advances in June 2025.
Technology based on magnons
But wait, let’s take two steps back: What is the point of all that? It is all about technology, of course, not about magic. We live in a time in which artificial intelligence and the “Internet of Things” generate huge amounts of data. It is already apparent today that the current schemes of our information technology will soon no longer be able to cope with these volumes of data. A bottleneck threatens that will slow down technological advances.
As a solution to this problem, researchers have been proposing for some time to use electron spins as information carriers, or, more precisely, entire spin waves of sometimes hundreds of trillions of spins that oscillate together. Such collective spin excitations are called magnons and behave like a wave. With the help of lasers, they can be influenced and thus “controlled.” This could enable information transmission and storage in the terahertz range in the future.
Of course, there is a catch: One limitation, for example, is that we have so far only been able to excite magnons in the state of their lowest frequencies using light. As a result, the process falls short of its potential. For the technological exploitation of magnons, being able to influence their frequency, amplitude and lifetime would be a decisive pre-requisite.
The Konstanz research team led by Davide Bossini has now found a promising way to do just that. Surprisingly, the control is achieved by the direct optical excitation of magnon pairs, which are the highest frequency magnetic resonances in the material.
A huge surprise
“The result was a huge surprise for us. No theory has ever predicted it,” says Davide Bossini. Not only does the process work – it also has spectacular effects. By driving high-frequency magnon pairs via laser pulses, the physicists succeeded in changing the frequencies and amplitudes of other magnons – and thus the magnetic properties of the material – in a non-thermal way.
“Every solid has its own set of frequencies: electronic transitions, lattice vibrations, magnetic excitations. Every material resonates in its own way,” explains Bossini. It is precisely this set of frequencies that can be influenced through the new process. “It changes the nature of the material, the ‘magnetic DNA of the material,’ so to speak, its ‘fingerprint.’ It has practically become a different material with new properties for the time being,” says Bossini.
“The effects are not caused by laser excitation. The cause is light, not temperature,” confirms Bossini: “We can change the frequencies and properties of the material in a non-thermal way.” The advantages are obvious: The method could be used for future data storage and for fast data transmission at terahertz rates without the systems being slowed down by the pileup of heat.
No spectacular high-tech materials or rare earths are required as the basis for the process, but rather naturally grown crystals – namely the iron ore hematite. “Hematite is widespread. Centuries ago, it was already used for compasses in seafaring,” explains Bossini.
It is perfectly possible that hematite will now also be used for quantum research in the future. The results of the Konstanz team suggest that, using the new method, researchers will be able to produce light-induced Bose-Einstein condensates of high-energy magnons at room temperature. This would pave the way to researching quantum effects without the need for extensive cooling. Sounds like magic, but it is just technology and cutting-edge research.
Reference: “Dynamical renormalization of the magnetic excitation spectrum via high-momentum nonlinear magnonics” by Christoph Schönfeld, Lennart Feuerer, Julian Bär, Lukas Dörfelt, Maik Kerstingskötter, Tobias Dannegger, Dennis Wuhrer, Wolfgang Belzig, Ulrich Nowak, Alfred Leitenstorfer, Dominik Juraschek and Davide Bossini, 20 June 2025, Science Advances.
DOI: 10.1126/sciadv.adv4207
The research was funded by the German Research Foundation (DFG).
The project was carried out in the context of the Collaborative Research Centre SFB 1432 “Fluctuations and Nonlinearities in Classical and Quantum Matter beyond Equilibrium.”
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