© Peter Shanks
© Peter Shanks

Graphene turns electricity into light

Researchers have discovered a process in which a flow of electric current can exceed the speed of slowed-down light, producing an intense, focused beam.

This innovative way of converting electricity into visible radiation is manageable and efficient, the researchers say, and could lead to numerous potential applications.

Professors Marin Soljačić and John Joannopoulos, as well as Dr Ido Kaminer, of Massachusetts Institute for Technology (MIT), USA, and six other researchers based in Israel, Croatia, and Singapore have published their research in the online journal Nature Communications.

Kaminer, the lead author of the paper, said: “Graphene has this ability to trap light, in modes we call surface plasmons. Plasmons are a kind of virtual particle that represents the oscillations of electrons on the surface. The speed of these plasmons through the graphene is a few hundred times slower than light in free space.”

The discovery is significant in the generation of plasmons on a scale compatible with current microchip technology. Graphene-based systems such as this could be key components for the creation of new, light-based circuits: a major new direction in the evolution of computing technology toward smaller, more efficient devices.

“If you want to do all sorts of signal processing problems on a chip, you want to have a very fast signal, and also to be able to work on very small scales,” Kaminer continues. By using plasmons, as opposed to flowing electrons, for data storage, operating speeds can be up to one million times faster.

The research was supported by the US Army at MIT.

Read the published paper here.