▎ 摘　　要

Newly synthesized nanostructures of graphene appear as a promising breeding ground for new technology. Therefore it is important to identify the role played by the boundary conditions in their electronic features. In this contribution, we use the nonequilibrium Green's function method coupled to tight-binding theory to calculate and compare the current patterns of hexagonal graphene quantum dots, with contacts placed at different edge locations. Our results reveal the formation of current vortices when the geometry of the contact position is not centrosymmetric. That is when they are placed on nonfrontal armchairlike vertices of the quantum dot. The introduction of defects, leading to disorder, significantly alters the current behavior, distorting bulk vortices and annihilating the edge currents. Nevertheless, periodically distributed defects on the edge allow for the appearance of current loops that dodge the defects. The presence of current vortices suggests the use of graphene quantum dots as nanomagnets or magnetic nanosensors.