Electron energy-loss spectroscopy of electron states in isolated carbon nanostructures

Electronic states of an isolated nano-object made of single graphene layer have been successfully explored by means of electron energy-loss spectroscopy with high sensitivity and high spatial resolution. In further systematic study of various carbon nanostructures, the curvature and/or the interlayer coupling between adjacent graphene layers have been proved to govern the electronic states of carbon nanostructures. Using density functional theory, experimentally observed variations of the carbon $K(1s)$ near-edge fine structure have been ascribed mostly to the increasing curvature of the graphene layers.