  We provide a broad review of fundamental electronic properties of
two-dimensional graphene with the emphasis on density and temperature dependent
carrier transport in doped or gated graphene structures. A salient feature of
our review is a critical comparison between carrier transport in graphene and
in two-dimensional semiconductor systems (e.g. heterostructures, quantum wells,
inversion layers) so that the unique features of graphene electronic properties
arising from its gap- less, massless, chiral Dirac spectrum are highlighted.
Experiment and theory as well as quantum and semi-classical transport are
discussed in a synergistic manner in order to provide a unified and
comprehensive perspective. Although the emphasis of the review is on those
aspects of graphene transport where reasonable consensus exists in the
literature, open questions are discussed as well. Various physical mechanisms
controlling transport are described in depth including long- range charged
impurity scattering, screening, short-range defect scattering, phonon
scattering, many-body effects, Klein tunneling, minimum conductivity at the
Dirac point, electron-hole puddle formation, p-n junctions, localization,
percolation, quantum-classical crossover, midgap states, quantum Hall effects,
and other phenomena.
