Vórtices em pontos quântico de grafeno induzidos por um campo magnético

Abstract

In this work, we investigated the current densities pattern induced by a perpendicular external magnetic field on eigenstates of three types of graphene quantum dot (QD). Eingenstates are obtained by numerical diagonalization of the tight-binding Hamiltonian. We consider graphene quantum dots with square and triangular geometries with zigzag armchair edges. First, we obser how the energy spectrum of these quantum dots behaves in the presence of an external magnetic field and analyze how the geometries and sizes influence this result. Then we find the distribution of local current densities in the presence of an applied magnetic field, for each geometry mentioned above. Finally, we check if there are vortex states for these current densities, and how they relate to angular momentum states, in analogy to what we have for the case of semiconductor quantum dots.