  The diamagnetism of confined Dirac fermions submitted to a uniform magnetic
field in disordered graphene is investigated. The solutions of the energy
spectrum are used to discuss the orbital magnetism from a statistical
mechanical point of view. More precisely, by the technique of Green functions
the self-energy for short and long-ranged disorders is obtained. This allows us
to determine the susceptibility for short and long-ranged disorders together
with confinement. We compare our results with already published work and point
out the relevance of these findings to a systematic formulation of the
diamagnetism in a confining potential.
