Skyrmions are tiny magnetic whirlpools tucked into the spins of electrons inside certain materials. To the untrained eye they might look like curiosities, but to physicists they are a telling manifestation of topology — a kind of global wiring that makes these patterns extraordinarily robust. In practical terms, skyrmions behave like stable, mobile carries of magnetic information. That combination—topological protection plus nanoscale size—has long made them poster children of the next wave in data storage and processing, a branch of science sometimes called spintronics. Yet the leap from curiosity to controllable technology has required not just better materials but a way to write, erase, and move these textures with speed and precision. A team of researchers from Sorbonne Université in Paris, in collaboration with Imperial College London, has taken a bold step toward that dream by showing how light itself can sculpt a skyrmion lattice on a nanoscale playground made of gold.
The paper’s core claim is both conceptually elegant and practically provocative: a carefully arranged metasurface — a hexagonal lattice of gold nanodisks tucked on a glass substrate — can be driven by circularly polarized light to generate drift currents inside each disk. Those currents, and the counterpropagating “phantom” currents in the gaps between disks, set up a magnetic field pattern that winds into a Néel-type skyrmion texture right where the light hits. In other words, a topological magnetic lattice can be grown all-optically, with the same light that illuminates it. The lead authors Xingyu Yang, Chantal Hareau, Jack Gartside, and Mathieu Mivelle led the effort, working across Sorbonne Université’s Institut des NanoSciences de Paris and Imperial College London. The result sketches a pathway to ultrafast, on-demand control of magnetic order that could underpin future data storage and logic devices.
To appreciate why this matters, think about how light and magnetism have historically danced at arm’s length. Magnetic materials want to keep their spins aligned, storing information in the slow, stubborn orientation of those spins. Light, on the other hand, can push, twist, and attend to the electrons with astonishing speed and precision. The trick here is to use a magneto-optical effect that has been known for decades — the inverse Faraday effect — but to deploy it on a nanoscale metamaterial that organizes currents in a way that recreates a whole crystal of skyrmions. The researchers did not just demonstrate a single skyrmion; they showed a lattice, a regular array with the same symmetry as the underlying nanodisk network. That regularity is essential for any practical device concept, because orderly textures tend to behave more predictably in a circuit than a random clump of spins.
Turning light into magnetism at the nanoscale
At the heart of the experiment is the inverse Faraday effect, a magneto-optical phenomenon in which circularly polarized light can induce magnetization in a material. When light carries angular momentum and interacts with electrons in a metal, it nudges those electrons into a tiny, circulating drift — a drift current — that leaves behind a magnetic fingerprint. In a bulk piece of metal this is already a subtle, ultrafast effect; in a nanostructured landscape it becomes a very deliberate tool. The team modeled how a circularly polarized beam, striking a hexagonal array of gold nanodisks, creates currents that rotate in the same direction inside each disk while knitting across the lattice with a mirrored sense in the gaps. This spatial dance is what seeds the skyrmionic texture in the induced magnetic field just above the surface.
One of the clever moves in the study is how they leveraged the lattice symmetry to produce a pair of current patterns that are simultaneously present yet spatially offset. Within each disk, the drift current runs in a clear, directional loop. In the interstices — the little gaps between disks — a set of counterpropagating, or “phantom,” loops appear. The Biot–Savart law tells us that those currents generate magnetic fields that, when combined, yield an up-then-down topography of the magnetic field. The resulting structure is not a random swirl but a crystalline pattern, a skyrmionic texture that repeats across the metasurface with the same hexagonal symmetry as the disk array. This is the point where optics and magnetism meet in a predictable, engineerable way, not by nudging a material to form a skyrmion, but by shaping the light to write one directly into the field that surrounds the device.
Hexagonal hunger: building a skyrmion lattice
The geometry matters. The researchers chose a nanoscale unit cell in which each gold disk has a 50-nanometer radius and a 10-nanometer thickness. The lattice period — the distance between neighboring disks along one direction — tunes how the optical field concentrates and where the strongest helicity (the handedness of the polarization) shows up. Through simulations, they scanned various periods and identified a sweet spot around a 120-nanometer period that produced a nearly integer skyrmion number, close to Q = 1, while maximizing contrast between the maxima and minima of the magnetic field. In this regime, the magnetic field at the center of a disk points in one direction, and within the gaps it flips, creating the classic swirling pattern that defines a Néel-type skyrmion. A skyrmion number near 1 means the texture winds almost exactly once as you move from the center to the edge of a unit cell—a clean, robust topological feature that’s less likely to degrade under small perturbations.
Crucially, the topology is not fixed in stone; it can be flipped with the light’s helicity. The same metasurface exposed to right-handed circular polarization produced one skyrmion texture, while left-handed light reversed the sense of the drift currents and flipped the skyrmion’s sign. In a larger swath of the metasurface, that means a material could be “re-programmed” optically to hold a positive or negative skyrmion lattice without touching a single magnetic material with a magnetic field or electrical current. The authors describe this as a form of all-optical control with the potential for ultrafast timescales, since the writing happens as fast as light can respond and the spins can reconfigure almost instantaneously once the optical field is on the scene.
What it could unlock in data and light
All-optical creation of skyrmions has been a long-sought goal because it would offer a way to write and erase information with light instead of with electrical currents. In a world where data storage and on-chip processing increasingly push the limits of energy efficiency and speed, being able to generate a stable, programmable lattice of topological textures on demand could be a game changer. Skyrmions promise low-energy manipulation: they can be moved with tiny currents, stored densely due to their nanoscale footprint, and exhibit robustness against defects because of their topology. The prospect of confining and reconfiguring such textures over large areas with nothing but light hints at a future where magnetic memories and neuromorphic-like processors could be woven into photonic circuits, blending the best of both worlds—magnetic stability and optical speed.
There are, of course, important steps between a nanoscale demonstration on a plasmonic metasurface and a full-fledged device ready for data centers. Translating a surface-anchored skyrmion lattice into a practical memory element would require coupling the optical field to a magnetic medium that can host and transport the texture, as well as robust ways to read out the skyrmion state without destroying it. The researchers emphasize that their work is a foundational demonstration: an optical handle that orchestrates magnetic topology at the nanoscale and on a lattice, with the promise of integration into real materials and devices. If such an integration can be realized, the pathway to ultrafast, low-power memory, logic, and even optical-quantum interfaces could become a tangible reality in the not-too-distant future.
As a closing thought, this work is a vivid reminder that the boundary between light and matter is not a barrier but a toolkit. When shaped with precision, light does not merely illuminate; it can sculpt the magnetic landscape at the smallest scales, writing patterns that persist and can be read or re-written with surgical optical control. The study’s hexagonal metasurface shows that the language of topology can be translated into a practical technology by arranging the right nanostructures and the right light. It is a kind of modern alchemy: not turning lead into gold, but turning photons into spin—coherently, reversibly, and at scales that could one day power the heart of future information systems.
In their acknowledgments, the authors point to the collaboration between Sorbonne Université, CNRS, INSP, and Imperial College London, with lead authors Yang, Hareau, Gartside, and Mivelle guiding the effort. The research stands as a snapshot of what cross-disciplinary teams can achieve when optics, magnetism, and nanofabrication converge on a single goal: to bend light into a tool that sculpts magnetism with precision and speed. If the idea proves scalable to real devices and materials, the road from a laboratory demonstration to a technology platform could be shorter than many expect, fueled by the same light that has illuminated human curiosity for millennia.
