Bilayer graphene is another step toward graphene electronics

August 11, 2011
Made of a single sheet of carbon atoms, graphene can be spun at the fastest rate of any known macroscopic object. Image credit: Wikimedia Commons.

The Nobel Prize winning scientists Professor Andre Geim and Professor Kostya Novoselov have taken a huge step forward in studying the wonder material graphene and revealing its exciting electronic properties for future electronic applications.

Writing in the journal Science, the academics, who discovered the world's thinnest material at The University of Manchester in 2004, have revealed more about the of its slightly fatter cousin – bilayer graphene.

The researchers, from the universities of Manchester, Lancaster (UK), Nijmegen (the Netherland) and Moscow (Russia), have studied in detail the effect of interactions between electrons on the electronic properties of bilayer graphene.

They used extremely high-quality bilayer graphene devices which are prepared by suspending sheets of the material in vacuum. This way most of the unwanted scattering mechanisms for electrons in graphene could be eliminated, thus enhancing the effect of electron-electron interaction.

The latter could be seen as strong changes in the low-energy electronic spectrum – it becomes strongly anisotropic, or directionally dependent. This is the first effect of its kind where the interactions between electrons in graphene can be clearly seen.

The reason for such unique electronic properties is that quasiparticles (electrons and holes, which carry electric current) in this material are very different from those in any other metals. They possess chiral symmetry (a symmetry between electrons and holes) of the sort which exist between particles and antiparticles in high-energy physics.

Due to such properties graphene-based are sometimes called 'CERN on a desk' – referencing the Large Hadron Collider in Switzerland. This is just one of the reasons why the electronic properties are particularly exciting and often bring surprises.

Professor Geim and Professor Novoselov's pioneering work won them the for Physics in 2010 for "groundbreaking experiments regarding the two-dimensional material graphene".

The pair, who have worked together for more than a decade since Professor Novoselov was Professor Geim's PHD student, used to devote every Friday evening to 'out of the box' experiments not directly linked to their main research topics.

One Friday, they used Scotch tape to peel away layers of carbon from a piece of graphite, and were left with a single atom thick, two dimensional film of carbon – graphene.

Graphene is a novel two-dimensional material which can be seen as a monolayer of carbon atoms arranged in a hexagonal lattice. When two layers of graphene are bonded in a certain manner, they form bilayer graphene – a very interesting and unusual material in its own right.

Both graphene and bilayer graphene possesses a number of unique properties, such as extremely high electron and thermal conductivities due to very high velocities of and high quality of the crystals, as well as mechanical strength.

Professor Novoselov said: "The technology of graphene production matures day-by-day, which has an immediate impact both on the type of exciting physics which we find in this material, and on the feasibility and the range of possible applications." Professor Geim added: "High-quality bilayer is certainly an exciting material in its own right, and it certainly has its own niche in applications."

Explore further: Graphene's 'quantum leap' takes electronics a step closer

Related Stories

Two graphene layers may be better than one

April 27, 2011

( -- Researchers at the National Institute of Standards and Technology have shown that the electronic properties of two layers of graphene vary on the nanometer scale. The surprising new results reveal that not ...

Toward a better understanding of bilayer graphene

October 26, 2010

( -- "Graphene is a very exciting material with a number of interesting possibilities, including for use in electronic devices," Pablo Jarillo-Herrero tells "However, all graphene systems are electronically ...

Recommended for you

Engineers create plants that glow

December 13, 2017

Imagine that instead of switching on a lamp when it gets dark, you could read by the light of a glowing plant on your desk.

Faster, more accurate cancer detection using nanoparticles

December 12, 2017

Using light-emitting nanoparticles, Rutgers University-New Brunswick scientists have invented a highly effective method to detect tiny tumors and track their spread, potentially leading to earlier cancer detection and more ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.