Nanoscale Light Conduction by Borophen

In a groundbreaking discovery, researchers at Kiel University (CAU) and the University of California, San Diego have uncovered unique properties in the two-dimensional metal Borophene that could revolutionise the field of nanophotonics.

The team, led by Professor Nahid Talebi from the Institute of Experimental and Applied Physics at CAU, along with guest scientist Professor Yaser Abdi, has found that Borophene exhibits hyperbolic polaritons, a phenomenon where light and matter interact in a distinct manner, creating a hybrid wave. This discovery was made in the visible range, a significant development as it aligns with the wavelengths of many quantum communication systems.

The unique interaction between light and electrons in Borophene results in hyperbolic polaritons that spread differently fast and strong depending on direction, a phenomenon known as anisotropy. This direction-dependent behaviour is a result of the atomic structure of Borophene, which forces electrons into preferred paths.

One of the key advantages of hyperbolic polaritons in Borophene is their ability to concentrate light extremely and guide it below the diffraction limit. This is crucial for smaller and more precise optical systems, paving the way for advancements in compact photonic components and highly sensitive optical sensors.

The team at CAU was the first to observe hyperbolic polaritons in Borophene in the visible range. They used cathodoluminescence spectroscopy to study the optical properties of Borophene, and an image of Borophene on a perforated gold transmission electron microscope grid was obtained.

Borophene's metallic, atomically thin, and naturally anisotropic properties make it a unique platform for guiding visible light at the nanoscale. These properties could potentially be integrated into microscopes, opening up new possibilities for nanophotonics.

The work lays the foundation for future technologies, including compact photonic components, highly sensitive optical sensors, and advanced microscopy methods. The discoveries made by the team at CAU and UC San Diego could have far-reaching implications for the development of next-generation optical technologies.