We provide a semiclassical description of the electronic transport through
graphene n-p junctions in the quantum Hall regime. A semiclassical
approximation for the conductance is derived in terms of the various snake-like
trajectories at the interface of the junction. For a symmetric (ambipolar)
configuration, the general result can be recovered by means of a simple
scattering approach, providing a very transparent qualitative description of
the problem under study. Consequences of our findings for the understanding of
recent experiments are discussed.Comment: 10 pages, 2 figure