INTERLAYER INTERACTION OF 2 GRAPHENE SHEETS AS A MODEL OF DOUBLE-LAYER CARBON NANOTUBES

To aid the analysis of interlayer interactions in double-layer carbon nanotubes, the interactions between two graphene sheets have been anal ytically examined within the framework of the Huckel approximation. Al though there is a limitation to apply the present results to the actua l double-layer nanotubes, it has been suggested that a certain interla yer interaction mode affects the metallic state of a nanotube with the direct zero-energy gap changing into the indirect one and, moreover, that other mode even changes into non-metallic state. Copyright (C) 19 97 Elsevier Science Ltd.