Energy-gap modulations of graphene ribbons under external fields:: A theoretical study

Here, we address a theoretical study of electronic properties of carbon ribbons under the effect of external electric and magnetic fields. The Peierls approximation is used to incorporate the magnetic field within a tight-binding picture. A charge self-consistent calculation is adopted to analyze the gap modulations induced by the application of the external electric field and compared with simple models. We show that depending on the ribbon geometries and field intensities, a large variety of electronic situations may be achieved, suggesting possible mechanisms for gap engineering of such carbon nanomaterials.