Scientists hail breakthrough in manipulation of light

The discovery could lead to major advances in everything from biosensors, to high-speed, low-energy computers

'Twistronics' involves layering and twisting two-dimensional materials like graphene. (Getty Images/iStockphoto)

Scientists have managed to manipulate the flow of light in extreme ways through a concept known as “twistronics”.

An international team of researchers used the technique to rotate layers of the ultra-thin, two-dimensional material molybdenum trioxide in order to manipulate light in highly unusual ways.

Light usually diffracts when it travels around objects, but using a “magic twist angle” of 1.1 degrees the team were able to prevent optical diffraction.

This enabled robust light propagation in a tightly focused beam at desired wavelengths – an ideal feature for nanoscience and photonic technologies.

The discovery could lead to major advances in everything from biosensors, to high-speed, low-energy computers.

The lack of diffraction also makes it much easier to resolve nanoscale images through optical microscopy.

“While photons – the quanta of light – have very different physical properties than electrons, we have been intrigued by the emerging discovery of twistronics, and have been wondering if twisted two-dimensional materials may also provide unusual transport properties for light, to benefit photon-based technologies,” said Andrea Alù, founding director of the CUNY ASRC’s Photonics Initiative and Einstein Professor of Physics at The Graduate Center.

“To unveil this phenomenon, we used thin layers of molybdenum trioxide. By stacking two of such layers on top of each other and controlling their relative rotation, we have observed dramatic control of the light guiding properties.”

Professor C.W. Qiu from the National University of Singapore added: ”Our study shows that twistronics for photons can open truly exciting opportunities for light-based technologies, and we are excited to continue exploring these opportunities.”

The results of the study are published this week in the journal Nature.