Researchers from the NIMFEIA consortium have discovered a new way to make tiny magnetic structures behave in unexpectedly rich and useful ways. The results are published in Science.
Inside microscopic magnetic disks, magnetism naturally forms a vortex, a bit like a tiny whirlpool that can be seen in the top part of the image above. Normally, this vortex responds to stimulation with a single, simple rhythm. What the researchers found is that, when gently driven with microwaves, the vortex can start to dance in time, producing many perfectly spaced rhythms at once — much like a musical note turning into a chord.
This phenomenon belongs to a class of effects called Floquet states, where systems that are rhythmically driven develop new behaviors that do not exist at rest. Until now, creating such states usually required powerful laser pulses. The surprise here is that very little energy is needed: a barely noticeable motion of the vortex core arounds its equilibrium position in the disk center (as shown in the bottom part of the image above) is enough to reorganize the entire magnetic system.
Why does this matter? Because these multiple rhythms form a frequency comb, a tool that can link systems operating at very different speeds. In the future, this could help connect conventional electronics, magnetic devices, and even quantum technologies, which normally “speak different languages.”
In simple terms: the team showed that time itself can be used as a new control knob. By making magnetism oscillate in just the right way, one can unlock new states of matter — with exciting implications for energy-efficient computing and information technologies.
If you want to know more about this topic, check out our article “Self-induced Floquet magnons in magnetic vortices” in Science and the press release (available in German and in Dutch as well).
