Nanowerk June 11, 2020
As recent research showed how superconductivity is achieved in a pair of stacked graphene layers that were rotated to the “magic twist angle” and careful control of rotational symmetries can unveil unexpected material responses. Now an international team of researchers (Singapore, USA – City University of New York, Australia, China) has discovered that an analogous principle can be applied to manipulate light in highly unusual ways. They stacked two thin sheets of molybdenum trioxide and rotated one of the layers with respect to the other. When the materials were excited by a tiny optical emitter, they observed widely controllable light emission over the surface as the rotation angle was varied preventing optical diffraction and enabling robust light propagation in a tightly focused beam at desired wavelengths. The findings help advance light-driven technologies, including nano-imaging devices; high-speed, low-energy optical computers; and biosensors…read more. TECHNICAL ARTICLE
A bilayer of molybdenum trioxide supports highly unusual light propagation along straight paths when the two layers are rotated with respect to each other at the photonic magic angle. (Image: ASRC)