Electronic properties of polygonal defects in graphitic carbon sheets

Remarkable features of local density of states (LDOS) at a single (Formula presented)-membered ring defect (Formula presented) in monolayered graphite are described. Based on the (Formula presented)-fold rotational symmetry at the center of the (Formula presented)-membered ring, the wave functions and the spectra of these systems are classified into (Formula presented) kinds of components according to the character of the rotational symmetry group. Based on the analysis using this symmetry, the LDOS can be considered as broadened energy levels of the corresponding isolated (Formula presented)-membered ring molecule. The (Formula presented)-membered ring defect with the large-(Formula presented) limit can be considered a screw dislocation in the graphite. The value of its LDOS approaches zero as the inverse of the logarithm of the energy at the band edges and at the band center.