05 December 2016 Polaritons in layered two-dimensional materials

Study published in Nature Materials points to the potential of layered 2D materials for nano-photonics and nano-optoelectronics An international group of experts led by the University of Minnesota, including ICREA Prof at ICFO Frank Koppens, have published a study in Nature Materials entitled “Polaritons in layered two-dimensional materials” which highlights how manipulation of 2D materials could make our modern day devices faster, smaller, and better.

Two-dimensional materials are a class of nanomaterials that are only a few atoms in thickness. Electrons in these materials are free to move in the two-dimensional plane, but their restricted motion in the third direction is governed by quantum mechanics. Research on these nanomaterials is still in its infancy, but 2D materials such as graphene, transition metal dichalcogenides and black phosphorus have garnered tremendous attention from scientists and engineers for their amazing properties and potential to improve electronic and photonic devices.

In this study, researchers have teamed up to examine the optical properties of several dozens of 2D materials. The goal of the paper is to unify understanding of light-matter interactions in these materials among researchers and explore new possibilities for future research.

They discuss how polaritons, a class of quasiparticles formed through the coupling of photons with electric charge dipoles in solid, allow researchers to marry the speed of photon light particles and the small size of electrons. By exciting the polaritons in 2D materials, electromagnetic energy can be focused down to a volume a million times smaller compared to when its propagating in free space.

Researchers agree that layered two-dimensional materials offer tremendous opportunities for practical applications, ranging from sensing and fingerprinting minute amounts of biomolecules, to applications in optical communications, energy harvesting and security imaging.

The new study also examined the possibilities of combining 2D materials. Researchers point out that every 2D material has advantages and disadvantages. Combining these materials create new materials that may have the best qualities of both.