Abstract
A -electron network in nanographite systems with zigzag edges exhibits strongly localized edge states, which are expected to have peculiar properties. We study effects of electron-electron interactions on ground-state properties of zigzag nanographite ribbons and open-ended zigzag nanotubes by means of the weak-coupling renormalization group and the density-matrix renormalization-group method. It is shown that the ground state is a spin-singlet Mott insulator with finite charge and spin gaps. We also find that the edge states are robust against the electronic correlations, resulting in edge-effective spins that can flip almost freely. The schematic picture for the low-energy physics of the systems is discussed.
- Received 10 March 2003
DOI:https://doi.org/10.1103/PhysRevB.68.035432
©2003 American Physical Society