Graphene discovery could be vital to future nanotechnology

Researchers from the London Centre for Nanotechnology (LCN) have made a discovery that could help graphene play a key role in the future of nanotechnology.

The team of scientists observed the surface of graphene sheets and found a series of ridges on the material that it believes could help it further exploit the potential of graphene and develop the understanding of superconductivity.

Graphitic materials have an electronic structure that can be readily manipulated through electrostatic or chemical doping, resulting in a rich variety of electronic states.

In an experiment, calcium intercalated superconductor (CaC6) was heavily doped with electrons and observed with scanning tunnelling microscopy.

Chris Howard, one of the lead investigators on the project and a researcher at LCN, said: ‘At the time we were looking more generally at a graphite intercalation compound and not really from the point of view of graphene. We were trying to understand this material because it superconducts.’

Howard said he and his team did not expect to see a set of striking one-dimensional electronic waves. After some electronic structure measurements, the group was able to conclude that they were looking at ‘charged density waves’.

’The electron density is normally relatively uniformly distributed across a metal. In certain cases, the overall energy of the system can be lowered if these electron densities are distributed unevenly and these charged density waves are formed on the surface, where the electron density appears bunched.’

According to Howard, not only is this breakthrough of interest to theoretical scientists hoping to advance graphene technology, it could also be used as a way of storing information. ‘So if the stripes are in one direction, you could prescribe them to one particular state and this could be controlled,’ he said.

‘Understanding graphene’s electronic properties is one of the key things we must do in order to exploit it,’ he said. ’Some people believe that the stripes are closes related to superconductivity and understanding this relationship is very important to try and fully understand superconductivity, which has lots of applications, such as in MRI scanners and levitating trains.’