Electronic interwall interactions and charge redistribution in multiwall nanotubes

Using density functional theory, we calculate the charge redistribution incurred upon forming multiwall carbon nanotubes, or by sandwiching initially isolated single-wall nanotubes between graphene layers. In these systems, we observe a significant charge transfer between the \ensuremath{\pi} electron system of the tube walls and a newly formed interlayer state. We discuss the direction of charge flow in terms of the interlayer hybridization and work function differences in the composite systems.