Niels Bohr Lecture by Konstantin Novoselov
Graphene: Materials in the Flatland
When one writes by a pencil, thin flakes of graphite are left on a surface. Some of them are only one angstrom thick and can be viewed as individual atomic planes cleaved away from the bulk.
This strictly two dimensional material called graphene was presumed not to exist in the free state and remained undiscovered until the last year. In fact, there exists a whole class of such two-dimensional crystals. The most amazing things about graphene probably is that its electrons move with little scattering over huge (submicron) distances as if they were completely insensitive to the environment only a couple of angstroms away. Moreover, whereas electronic properties of other materials are commonly described by quasiparticles that obey the Schrödinger equation, electron transport in graphene is different: It is governed by the Dirac equation so that charge carriers in graphene mimic relativistic particles with zero rest mass. The very unusual electronic properties of this material as well as the possibility for it's chemical modification make graphene a promising candidate for future electronic applications.
Recent progress in graphene samples production allowed for a dramatic improvement in quality. Thus, mobilities of the order of 106 cm2/Vs can be routinely achieved in mono- and bi-layer graphene samples. This brought an influx of novel phenomena, previously non-observable in this material. The influence of electron-electron interaction become dominant and exhibit itself in spectrum modification, fractional quantum Hall effect, etc.
Konstantin Novoselov, School of Physics and Astronomy, University of Manchester