- Researchers demonstrate room-temperature laser control of magnons in thin magnetic materials
- Visible light pulses tune magnetic frequencies without cryogenic conditions
- Nanometer-scale magnets show promise for faster storage and non-silicon computing
Researchers have demonstrated a new way to tune magnetic behavior in extremely thin materials using visible laser pulses at room temperature.
The work focuses on controlling magnons, which are collective spin excitations that play a key role in magnetic devices.
The study, published in Nature communicationshows that nanometer-thick magnets can have their magnon frequencies adjusted both up and down as needed. The material used is only 20nm thick, making it compatible with dense electronic designs.
Countless possibilities
Magnons are already central to technologies such as hard drives and new spin-based computing concepts. Being able to control their frequency precisely has long been seen as a requirement for practical devices.
In previous experiments, similar effects were only achieved using mid-infrared lasers, cryogenic temperatures or bulky materials. These limitations limited any realistic path toward commercial use.
In this new work, the researchers instead used short laser pulses of visible light combined with a modest external magnetic field below 200mT. This allowed magnon frequencies to be shifted by as much as 40 percent from their original value.
The experiments were performed at room temperature using a bismuth-substituted yttrium iron garnet film grown on a gadolinium scandium gallium garnet (GSGG) substrate. The film’s low attenuation and strong magneto-optical response proved crucial.
By adjusting laser intensity and magnetic field strength, the team could reliably choose whether the magnon frequency increased or decreased.
This level of control comes from the interplay between optical heating, magnetic anisotropy and the applied field.
The laser pulses act as an ultra-fast tuning mechanism rather than a simple heat source. They temporarily change the material’s magnetic stiffness, which directly changes how fast magnons oscillate.
Because the effect operates on nanosecond time scales, it opens the door to magnetic logic elements that can be reconfigured almost instantaneously.
Such devices could avoid some of the thermal and scaling limits faced by silicon electronics.
The combination of room-temperature operation, visible-light control, and nanometer-scale thickness means that this approach could fit into future storage, signal processing, and spin-based computing systems.
In short, the research can help make everyday technology faster and more efficient, with one of the most obvious applications being data storage.
Hard drives and large cloud servers rely on magnetic materials, and being able to control them more precisely with light could make it possible to write and move data much faster than it is today.
It could also create new kinds of computer chips that use magnetism instead of electric current to process information.
These would produce less heat and use less power, which could lead to quieter laptops, longer battery life and — the holy grail for hyperscalers — data centers that are cheaper to run.
Another possible use is hardware that can change what it’s doing on the fly. Instead of a chip being built for a single task, light could be used to change its behavior almost instantaneously, allowing one piece of hardware to tackle different tasks.
Because the effect works at room temperature and in layers thinner than a human hair, it’s also not limited to lab experiments, meaning it could eventually be built into the phones, computers and portable storage systems people already use every day.
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