  The absence of backscattering in metallic nanotubes as well as perfect Klein
tunneling in potential barriers in graphene are the prominent electronic
characteristics of carbon nanostructures. We show that the phenomena can be
explained by a peculiar supersymmetry generated by a first order Hamiltonian
and zero order supercharge operators. Like the supersymmetry associated with
second order reflectionless finite-gap systems, it relates here the low-energy
behavior of the charge carriers with the free particle dynamics.
