World's lightest mirror is made from a few hundred atoms
Using just a few hundred identical atoms, physicists at the Max Planck Institute of Quantum Optics have pieced together the world’s lightest mirror. Despite having a surface measured in mere microns and being invisible to the naked eye, the one-of-a-kind device is seen as a powerful new tool for the study of quantum optical phenomena.
While the size of the mirror itself is incredibly small, with a diameter of around seven microns and a thickness of several tens of nanometers, it required a gigantic two-ton apparatus with more than a thousand optical components to create it. This machine enabled the team to engineer an artificially designed structure known as a metamaterial, consisting of a single structured layer of a few hundred identical atoms.
These atoms are organized in such a way that they form a two-dimensional array in a lattice shape, which is formed via interfering laser beams. This careful arrangement suppresses a diffuse scattering of light and channels it into a steady beam instead, while also allowing incoming photons to repeatedly bounce between the atoms before creating a very strong reflection.
The strong reflections offered by this incredibly tiny and lightweight mirror open up entirely new possibilities in the field of quantum theory, particularly those concerning the interplay between light and matter and the physics of photons. It could also enable the engineering of new and advanced quantum devices.
“Many new exciting opportunities have been opened, such as an intriguing approach to study quantum optomechanics, which is a growing field of studying the quantum nature of light with mechanical devices,” explains David Wei, Doctoral researcher and second author. "Or, our work could also help to create better quantum memories or even to build a quantum switchable optical mirror. Both of which are interesting advancements for quantum information processing.”
The research was published in the journal Nature.