Transporte balístico em dispositivos de grafeno nanoestruturados

Abstract

In this dissertation, we studied the electronic properties of a graphene nanoestructure under influence of external fields. We considered the application of an uniform transversal electric field and an uniform perpendicular magnetic field. Using a nearest-neighbor Tigh-binding model, we investigated how those fields change the band structure and the local density of states (LDOS) of the system. Then, we studied the transport properties of nanostructures. We assumed ballistic transport due to the long mean free path of graphene. Through a numerical model that it consists in solving the Tight-binding Hamiltonian in real space and the combination of the boundary conditions between the central region and the reservoir, we calculated the transmission coefficients for two specifics systems: First, for a graphene ribbon under the influence of a transversal electric field in a region of finite length; Next, for a three terminal ballistic junction (JBTT) of graphene under the influence of a transversal electric field in the region immediately before the junction.