NBIA Colloquium by Gordon Semenoff

The Relativistic World of Graphene

Gordon Semenoff
(University of British Columbia)

Graphene is a two-dimensional semimetal where the electron obeys an emergent relativistic Dirac equation. The resulting electronic properties of this substance make it both a fascinating case study in condensed matter physics and a promising new material for electronics technology.

It also offers a novel testing ground for fundamental issues associated with the quantization of the relativistic particle, such as zitterbewegung and the Schwinger and Klein effects which have proven difficult to test in the particle physics world, but are visible in and have profound effects on the physics of graphene.  As well, graphene electrons are putatively strongly coupled and some effects of strong interactions, such as dynamical symmetry breaking and the fractional quantum Hall effect have been
observed. 

This provides a simple example of the symmetry breaking phenomenon as well as posing a puzzle as to why, if interactions are strong, so much of the physics of graphene is described by weakly interacting, or even non-interactiong electrons.  Attempts at some insight into this question will be presented.