Skyrmions become colorful now!

Light Publishing Center, Changchun Institute of Optics, Fine Mechanics And Physics, CAS

Optical skyrmions, tiny knots of light known for their robustness against noise, are promising candidates for the next generation of information carriers. However, their real-world application has been stalled by a major limitation: they could only be generated in narrow bands of color. Current technologies, like metasurfaces and microcavities, rely on resonant effects that are highly sensitive to specific wavelengths. This has made it nearly impossible to generate broadband skyrmions on a chip—until now.

In a new paper published in eLight, a team of scientists led by Professors Jingbo Sun and Ji Zhou of Tsinghua University, along with Professor Yijie Shen of Nanyang Technological University, has developed a revolutionary solution. They created an on-chip platform using ferroelectric spherulites—dome-shaped microstructures that form naturally through self-assembly.

Unlike traditional methods that require complex nanofabrication, these spherulites act as non-resonant optical elements. The team leveraged the unique properties of these structures to generate stable optical skyrmions across the entire visible spectrum, from blue to red light (450 to 785 nanometers).

“The key advantage is that we avoid the resonance constraints of artificial nanostructures,” the researchers explained. “Our platform uses the natural focusing power of the dome shape. When light hits the structure, it creates a specific texture, or skyrmion, without being picky about the color.”

This mechanism proved remarkably stable, maintaining its topological properties over long distances. Furthermore, the team demonstrated dynamic control over these light patterns. By simply adjusting the input light, they could switch between different types of topological quasiparticles, including skyrmions and biskyrmions.

The discovery also hints at quantum applications. The team observed signs of spontaneous parametric down-conversion within the material, suggesting the potential to generate entangled photon pairs with topological features.

“This breakthrough merges high-capacity data transmission with topological protection,” the scientists forecast. “It opens new avenues for both classical and quantum communication technologies, paving the way for faster and more secure optical networks.”