A research group at Stuttgart has manipulated light through its interaction with a metal surface to exhibit completely new properties. Researchers have published their findings in Nature Physics.
“Our results add another chapter to the emerging field of Skyrmion research,” Professor Harald Giessen, head of the Fourth Institute of Physics of the University of Stuttgart proclaimed, whose group achieved this progress. The team demonstrated the existence of “light bags” of light on the surface of a metal layer.
A better understanding of physical phenomena
Skyrmons are a mathematical description of structures similar to vortex that help researchers better understand fundamental physical relationships. In recent years, this theoretical concept has been confirmed experimentally in a wide range of areas, including magnetic solids and material surfaces. The Giessen group has now investigated whether the light that drives the structured surface of a thin gold layer is made as Skyrmion bags that follow specific symmetries. These bags consist of Skyrmons contained within a larger Skyrmion. For their experiment, the researchers recorded fine slots in the form of two twisted hexagons on the gold surface with each hexagon generating a Skyrmion light field.
Directed manipulation of light fields
“Then we observed an overlap of two Skyrmion light fields, of which the Skyrmion bags were formed,” explains Julian Schwab, the main author of the publication and doctoral student in the Giessen research group. Even more surprising, the researchers could vary the number of Skyrmons gathered within the Skyrmion bags adjusting the degree to which the fields of light crooked each other. In other words, researchers can manipulate light fields specifically, thus giving them forms that do not generally occur. For experimental verification, Giessen’s team collaborated with a research group at the University of Duisburg-Essen, and for the theoretical description of the phenomenon, with a group in the technique in Haifa.
Fundamental research with application potential
Until now, this is still a fundamental physics. However, these light field skyrms exhibit extraordinary properties, which caused the imagination of researchers in terms of possible technical applications. It remains to be seen if the gold surface used by the Giessen team is to be seen for this purpose. “If someone finds an adequate material, our concept could be applied in microscopy,” says Giessen. We could achieve resolutions with specialized microscopes that would otherwise be impossible due to the limits established by the wavelength of light.