Tiny Light Box Merges States of Light, Matter

A nanosize light box, built from stacked atomically thin material, has demonstrated the ability to capture and amplify light and link light to matter at the nanolevel. The light box, created by researchers at Chalmers University of Technology, makes the alternation between light and matter take place so rapidly that it becomes impossible to distinguish between the two states. The discovery combines the work of two research teams at Chalmers — one team’s work with nanoantennas, and another team’s research into transition-metal dichalcogenide (TMDC) materials.

Using a box built from stacked atomically thin layers of the material tungsten disulfide, Chalmers researchers created a type of feedback loop in which light and matter become one. This new concept involves two distinct processes being housed in the same nanodisk. The box has a diameter of only 100 nm (0.00001 cm). It could lead to new fundamental research and more compact solutions in nanophotonics. Courtesy of Denis Baranov/Yen Strandqvist/Chalmers University of Technology.

TMDCs have a high refractive index, a characteristic that makes it possible to use TMCD materials to construct resonant nanoantennas. The researchers used a well-known TMDC material, tungsten disulfide, to create a tiny resonance box, in which the light is captured. The light box can support distinct Mie resonances and anapole states that can be tuned in wavelength over the visible and near-infrared range by varying the size and aspect ratio of the nanosize box. The light in the box bounces around at a specific “tone,” allowing the light energy to be efficiently transferred to the electrons of the TMDC material and back again.

According to the researchers, the light energy essentially oscillates between the states of lightwaves and matter when it is captured and amplified inside the box. They demonstrated this novel regime of light-matter interaction within a single light box made from tungsten disulfide with a diameter of just 100 nm.

“We have succeeded in demonstrating that stacked atomically thin materials can be nanostructured into tiny optical resonators,” professor Timur Shegai said. “Since this is a new way of using the material, we are calling this ‘TMDC nanophotonics.’”

“We have created a hybrid consisting of equal parts of light and matter,” researcher Ruggero Verre said. The discovery could support advances in fundamental research and contribute to more compact and cost-effective solutions in applied photonics.

The research was published in Nature Nanotechnology (https://doi.org/10.1038/s41565-019-0442-x).