  Graphene nanoribbons (GNRs) are natural waveguides for electrons in graphene.
Nevertheless, unlike micron-sized samples, conductance is nearly suppressed in
these narrow graphene stripes, mainly due to scattering with edge disorder
generated during synthesis or cut. A possible way to circumvent this effect is
to define an internal waveguide that isolates specific modes from the edge
disorder and allows ballistic conductance. There are several proposals for
defining waveguides in graphene; in this manuscript, we consider strain folds
and scalar potentials and numerically evaluate these proposals' performance
against edge and bulk disorder. Using the Green's function approach, we
calculate conductance and the local density of states (LDOS) of zigzag GNRs and
characterize the performance of these different physical waveguiding effects in
both types of disorder. We found a general improvement in the electronic
conductance of GNR due to the presence of the internal waveguiding, with the
emergence of plateaus with quasi-ballistic properties and robustness against
edge disorder. These findings are up to be applied in modern nanotechnology and
being experimentally tested.
