  The Dirac point and linear band structure in Graphene bestow it with
remarkable electronic and optical properties, a subject of intense ongoing
research. Explanations of high electronic mobility in graphene, often invoke
the masslessness of electrons based on the effective relativistic
Dirac-equation behavior, which are inaccessible to most undergraduate students
and are not intuitive for non-physics researchers unfamiliar with relativity.
Here, we show how to use only basic concepts from semiconductor theory and the
linear band structure of graphene to explain its unusual effective mass and
mobility, and compare them with conventional metals and semiconductors. We
discuss the more intuitive concept of transverse effective mass that emerges
naturally from these basic derivations, which approaches zero in the limit of
undoped graphene at low temperature and is responsible for its extremely high
mobility.
