Electronic Structure of Graphene with a Topological Line Defect

• Published in: Journal of the Physical Society of Japan 2011-01, Vol.80 (1), p.013709-013709-4
• Main Authors: Okada, Susumu, Kawai, Takazumi, Nakada, Kyoko
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic structure of nanoscale materials : clusters, nanoparticles, nanotubes, and nanocrystals; Exact sciences and technology; Physics
• ISSN: 0031-9015; 1347-4073
• DOI: 10.1143/JPSJ.80.013709

Using the first-principle total-energy procedure within the framework of density functional theory, we study the electronic structure of graphene with a topological line defect that is comprised of a pair of fused pentagons and an octagon. We find that introduction of the topological line defect effectively terminates the sp 2 network of graphene leading the flat dispersion band around the $\Gamma$ point. A detailed investigation of the wave function of this flat-band state reveals its edge-state nature, which is particular to graphene nanoribbons with zigzag edges. Our tight-binding molecular dynamics simulation also reveals that the topological line defect is spontaneously formed from defects in the graphene sheet when held at a temperature of 1000 K.