The first part of the present thesis investigates the electronic transport in strain-engineered
graphene, which has been proposed as a way to circumvent the problem of an absent bandgap
in this material. To that end, we calculate the conductivity, the shot noise and the
density of states in the Dirac-Kronig-Penney model, which describes the phase-coherent
transport in clean monolayer samples with a one-dimensional periodic modulation of
the strain and the electrostatic potential. We find that periodic strains induce large
pseudo-gaps and suppress charge transport in the direction of the strain modulation
while the effect for periodic electrostatic potentials is weakened by Klein tunnelling.
The second part then deals with the transport properties of graphene at charge neutrality
when disordered by adatoms or scalar impurities. A scattering theory for the Dirac equation
yields an analytic expression for the conductivity given a particular impurity configuration;
an averaging over impurity configurations is performed numerically. For strong magnetic
fields, the conductivity equals the ballistic value, while for weaker fields, a rich scaling
flow is obtained which is governed by fixed points of different symmetry classes. In the
absence of a magnetic field, a surprising rise of the conductivity is observed when increasing
the density of adatoms that are randomly arranged on sites of the same Bloch-phase
