Effect of disorder on the local density of states of a graphene nanoribbon with a barrier

We study the behavior of the local density of states in an armchair graphene nanoribbon with a potential barrier, in the presence of realistic disorder due to charged impurities. The main purpose of this study it to provide, for a simplified case, information useful to establish the feasibility of an estimation of the characteristics of the barrier from a measurement of the behavior of the local density of states in an equilibrium condition, as recently suggested in the literature. We discuss to which extent disorder limits the information that can be extracted from the local density of states.