Negative differential resistance in graphene nanotubes

Recently, extensive efforts have been devoted to the investigations of negative differential resistance behavior in graphene nanotubes. Graphene nanotubes have attracted attention as materials for flexible nanoelectronic devices. We theoretically investigate the electronic transport properties of an armchair Graphene nanotube by using tight-binding medel. By applying an external electric field along lattice length we want to compute the electrical current along the length of graphene nanotubes. We have calculated the electrical current by using the current operator in the Heisenberg picture. We observe that the electrical current is directly dependent on the probability amplitude of finding an electron at each site of the lattice. We have achieved a set of first-order differential equations for the probability amplitude of finding an electron and then solved them through the numerical computations. Our calculations reveal that these devices have a striking nonlinear feature and show notable negative differential resistance. Furthermore, the results indicate that there are quasi-ohmic regions. It is found the electronic transport properties are strongly dependent on the radius of graphene nanotubes. These findings suggest that the graphene nanotube is a promising candidate for the next generation nanoscale device.