Scientists at the University of Birmingham have created a skyrmion, a model of a structureless elementary particle in a beam of light. They used the structure of spheres in four dimensions to show the skyrmion in three dimensions.

Skyrmion is a mathematical model in particle physics used to model baryons, strongly interacting fermions made up of three quarks.

The team used state-of-the-art measurements to determine the exact structure of the skyrmion: a description of light, polarization (the direction in which light waves propagate), and phase (the vibration position of light waves) in four-dimensional space. They then projected a skyrmion field and a laser beam.

The Skyrmions have intrigued and challenged physicists for decades. Although we have made progress in 2D skyrmion research, we live in a 3D world. We need a system that can simulate the skyrmion in all its possible states in such a way that it can be measured. We realized that a ray of light was suitable for this, because we can control its properties and use it as a platform for modeling our skyrmions. With this approach, we will be able to understand these objects and use their scientific potential.

Mark Dennis, lead author of the study

These objects are geometrically complex. They resemble a complex system of interconnected rings that form a particle-like structure. The topological properties of the skyrmion are interesting – they can be distorted, stretched or compressed, but then they will definitely return to their original state. This reliability is one of the properties that scientists are most interested in in order to further use it. Such models help in the study of the early origin of the universe, the physics of exotic materials or cold atoms.

For the first time, a system demonstrating the behavior of skyrmions was proposed 60 years ago by the physicist of the University of Birmingham, Tony Skyrm.