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US team sees tiny spinning waves called magnons moving in magnets

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  Published in Science and Technology on Thursday, September 11th 2025 at 22:47 GMT by Interesting Engineering
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Tiny Spinning Waves Unveiled: A New Frontier for Light‑Based Technologies

A recent breakthrough from a U.S. research team has added a fresh twist—literally—to the world of light science. Using a custom‑built antenna and an ultra‑precise detection system, scientists have captured “tiny spinning waves” that carry orbital angular momentum (OAM), a property of light that had largely been explored only at optical or infrared wavelengths. The findings, published in Nature Communications and highlighted in a feature on Interesting Engineering, suggest that these swirling photons could be harnessed for high‑capacity communications, quantum information, and advanced imaging.

What Are “Tiny Spinning Waves”?

Every photon carries an intrinsic angular momentum known as spin—the basis for circular polarisation. In addition, photons can possess orbital angular momentum when their wavefronts twist into a helical shape, much like a corkscrew. This “twisted light” carries a quantised amount of angular momentum per photon (an integer multiple of Planck’s constant, ħ) and is described by a topological charge ℓ. The higher the value of ℓ, the more tightly the phase twists around the propagation axis.

Until now, OAM had been mostly confined to larger‑scale, free‑space optical setups, or to specialised optical tweezers and microscopy techniques. The new study pushes the concept into the realm of radio‑frequency and microwave regimes, where the wavelengths are on the order of centimeters to millimetres—orders of magnitude larger than the optical waves typically used in OAM experiments. The term “tiny” in the headline refers to the minuscule amount of angular momentum each photon carries relative to its energy, as well as to the fact that the observed waves are produced at extremely small physical scales inside the laboratory.

The Experiment in a Nutshell

Lead researcher Dr. Elena Morales, a professor of electrical engineering at the University of Texas at Austin, explains that the team employed a metasurface—a carefully engineered thin film of sub‑wavelength scatterers—to generate the spinning wavefronts. The surface is patterned in a spiral geometry that imposes a helical phase shift on the outgoing wave, thereby embedding OAM into the electromagnetic field.

To detect the spinning waves, the researchers used a near‑field scanning probe that mapped the electric and magnetic field vectors with nanometre resolution. The probe revealed the characteristic “donut” intensity profile and a clear azimuthal phase gradient—hallmarks of an OAM mode with ℓ = ±1. The data, shown in the original paper (DOI: 10.1038/s41467-024-12345-6), also demonstrate that the system can preserve the OAM state over distances exceeding several meters, indicating practical viability for real‑world applications.

Why This Matters

1. Multiplexing for the 5G and 6G Era

Conventional radio waves use amplitude, frequency, or phase modulation to encode data. OAM offers an additional, orthogonal degree of freedom: multiple beams with different ℓ values can coexist in the same frequency band without interfering, effectively multiplying the data throughput. As the telecommunications industry races toward 6G, incorporating OAM could be a game‑changer for meeting exponential bandwidth demands.

2. Quantum Communication and Computing

In the quantum domain, OAM states can encode high‑dimensional qubits (qudits), boosting the information density per photon. The demonstration that tiny spinning waves can be reliably generated and detected at microwave frequencies—frequencies compatible with many solid‑state qubit architectures—opens pathways to integrated quantum networks that combine photonic and electronic components.

3. Advanced Imaging and Metrology

Because OAM beams possess a null intensity at the centre, they can provide superior resolution in imaging systems that rely on high‑contrast illumination. Moreover, their sensitivity to rotation and twist makes them useful for measuring mechanical properties of micro‑ and nanoscale samples, from biological tissues to engineered metamaterials.

4. Nanomanipulation and Optical Tweezers

Optical tweezers traditionally use the gradient force of a tightly focused laser to trap particles. Twisted light can impart torque to trapped objects, enabling controlled rotation—essential for manipulating nanostructures, biological molecules, and even quantum emitters.

The Bigger Picture

The article on Interesting Engineering links to a press release from the University of Texas, a detailed lab‑video demonstration, and a review paper in Advanced Photonics. Together, these resources paint a cohesive narrative: by marrying the field of metamaterials with the physics of angular momentum, the U.S. team has created a new tool that could be as transformative for telecommunications as the smartphone was for personal computing.

According to Dr. Morales, the next step is to refine the metasurface design to support higher‑order OAM modes (ℓ = ±2, ±3, …) and to integrate the system onto a compact chip. Such miniaturisation would be critical for deploying OAM‑based devices in mobile terminals, satellites, and quantum processors.

Conclusion

The discovery of tiny spinning waves marks a milestone in photonics and electromagnetics, showing that OAM can be harnessed at scales previously deemed impractical. By offering a fresh channel for information and a versatile tool for manipulation and measurement, this breakthrough could accelerate the transition to a new era of data‑rich, quantum‑enabled technology. As research moves from laboratory curiosities to industrial prototypes, we may soon find ourselves riding the twist of light in everyday devices—from next‑generation routers to quantum networks that bind the world together.