  This is a short review of two-dimensional Dirac fermions in graphene and
similar systems such as boron nitride, quasi-2D organic salts
$\alpha$-(BEDT-TTF)$_2$I$_3$, artificial graphene with cold atoms in optical
lattices, etc. The emphasis is on magnetic field properties (semi-classical
quantization of cyclotron orbits, Landau levels, quantum Hall effect,
magneto-plasmons, magneto-phonon resonance, magneto-transport, etc.) and on
topological properties (Berry phase, winding number, inter-band effects,
merging transition of Dirac points, etc.).

Mesoscale and Nanoscale Physics