It's a sheet of carbon that looks like chicken-wire, just one atom thick. The charge carriers that conduct electricity through it move as if they had no rest mass, like photons, at just three-hundredths of the speed of light. Its in-plane strength exceeds that of diamond. And it has become the most active research subject in all of condensed-matter physics today. Now Andre Geim and Konstantin Novoselov have been awarded the 2010 Nobel Prize in Physics, for being the first to isolate and demonstrate the properties of this remarkable material, graphene.

The properties of graphene had been studied theoretically for decades, largely owing to the fact that it is the building block of both graphite and carbon nanotubes. But no one knew how to isolate a single sheet of the material. That changed in 2004, with Geim and Novoselov's demonstration of field-effect transistors built from flakes of graphite just a few atomic-layers thick1 – flakes that had been peeled off a block of highly oriented pyrolytic graphite using adhesive tape. Geim and Novoselov found that several of the flakes they'd isolated using their technique were in fact only a single-carbon-atom thick, and, although they hadn't yet built a device from it, this challenged the widely held expectation that a single layer of graphene would be too fragile to exist as a isolated sheet.

A short while later, they succeeded in making single-layer graphene devices2, and the electronic behaviour they observed in these devices was profound. Far beyond simple field-effect transistor action, they discovered an entirely new class of quantum Hall effect – dubbed the half-integer quantum Hall effect – and found that graphene's charge carriers exhibited behaviour similar to that of massless high-energy particles travelling at relativistic speeds.

Since then all manner of strange and exotic phenomena have been observed in graphene and its variants. These include: the Klein effect, in which charge carriers are able to pass right through high potential barriers as if they weren't there; the survival of the half-integer quantum Hall effect at room temperature; and another class of unconventional quantum Hall effect in bilayer graphene.

Yet the reason for much of the excitement about graphene is its potential for new technology. The speed and ease with which charge carriers move in graphene make it an obvious candidate to succeed silicon in high-speed computer chips. Its combination of high conductivity, inherent flexibility and near-perfect optical transparency make it attractive for solar cells, touch-screen displays and similar large-area devices. And its mechanical properties could enable a new generation of high-strength composites.


The Nobel Prize in Physics 2010

 Some of the research papers on graphene published in Nature Physics:

Unconventional quantum Hall effect and Berry's phase of 2π in bilayer graphene K. S. Novoselov, E. McCann, S. V. Morozov, V. I. Fal'ko, M. I. Katsnelson, U. Zeitler, D. Jiang, F. Schedin & A. K. Geim Nature Physics 2 177 – 180, (26 February 2006) doi:10.1038/nphys245 Abstract | Full Text | PDF

Chiral tunnelling and the Klein paradox in graphene M. I. Katsnelson, K. S. Novoselov & A. K. Geim Nature Physics 2 620 – 625, (20 August 2006) doi:10.1038/nphys384 Abstract | Full Text | PDF

Valley filter and valley valve in graphene A. Rycerz, J. Tworzydlo & C. W. J. Beenakker Nature Physics 3 172 – 175, (18 February 2007) doi:10.1038/nphys547 Abstract | Full Text | PDF

Observation of Landau levels of Dirac fermions in graphite Guohong Li & Eva Y. Andrei Nature Physics 3 623 – 627, (8 July 2007) doi:10.1038/nphys653 Abstract | Full Text | PDF

Quantum interference and Klein tunnelling in graphene heterojunctions Andrea F. Young & Philip Kim Nature Physics 5 222 – 226, (1 February 2009) doi:10.1038/nphys1198 Abstract | Full Text | PDF

Broken-symmetry states and divergent resistance in suspended bilayer graphene Benjamin E. Feldman, Jens Martin & Amir Yacoby Nature Physics 5 889 – 893, (27 September 2009) doi:10.1038/nphys1406 Abstract | Full Text | PDF

Energy gaps and a zero-field quantum Hall effect in graphene by strain engineering F. Guinea, M. I. Katsnelson & A. K. Geim Nature Physics 6 30 – 33, (27 September 2009) doi:10.1038/nphys1420 Abstract | Full Text | PDF