2007 Mott medal and prize
Professor Andre Geim
University of Manchester
For his discovery of a new class of materials – free-standing two-dimensional crystals – in particular graphene.
During the last three years Andre Geim and his colleagues have opened up a new field of condensed-matter physics by discovering a conceptually new class of materials – strictly two dimensional atomic crystals. Among them graphene – a free-standing single layer of graphite – occupies a very special place due to its truly remarkable properties. Graphene is only one atom thick but highly stable under ambient conditions and exhibits nearly perfect crystal quality. It is also highly conductive so that electrons confined within this atomic gauze travel submicron distances without scattering.
Geim has already demonstrated a ballistic ambipolar transistor based on graphene, which has significantly improved the prospects of carbon-based electronics, even though at this early stage major applications of graphene and other two dimensional materials are still awaiting further development. On the other hand, there is already no doubt about the exceptional new physics that graphene offers. Quasiparticles in graphene are not normal electrons described by the Schrödinger equation but behave like massless relativistic fermions described by the Dirac equation.
Geim and colleagues have proven this in a series of elaborate experiments where two new types of the quantum Hall effect (dubbed as half-integer and chiral) and the minimum (or Mott’s) quantum conductivity in the limit of no charge carriers were reported. The latter discoveries have opened a new paradigm of “relativistic-like condensed matter” where quantum relativistic phenomena can now be studied experimentally in a bench-top experiment.
Geim works extensively to embed science in society, with educational demonstrations on magnetic levitation (the “flying frog” experiment) as well as research on biomimetic adhesives exploiting the same physical mechanism as that used by geckos when they climb (“gecko tape”). Through this and his discovery of graphene Geim has attracted worldwide media attention.