We theoretically study the electronic states in graphene ribbons which are strongly aected by the edge states, the peculiar non-bonding molecular orbitals localized along the zigzag edges of the ribbons. New kinds of edge localized electronic states w...
We theoretically study the electronic states in graphene ribbons which are strongly aected by the edge states, the peculiar non-bonding molecular orbitals localized along the zigzag edges of the ribbons. New kinds of edge localized electronic states with spinand charge polarizations are found in the mean eld solutions of the extended Hubbard model with onsite and nearest-neighborCoulomb repulsions. These novel states appear due to the interplay between the edge states and the Fermi instabilities. We alsoexamine the competition between the charge polarized state and the spin polarized state to draw a phase diagram depending onCoulomb parameters. The results obtained by the mean eld calculations with the extended Hubbard model modied to include Coulomb integrals provide useful insights to understand and functionalize the nanoscale materials.