Physical chemistry of nanographene edges:edge states and their electronic and magnetic functions

纳米石墨烯的电子结构关键取决于边缘几何形状。这是物理学中无质量狄拉克费米子边界条件的结果，而它可以在化学芳香性的基础上理解。我们利用STM/STS、AFM、拉曼散射、NEXAFS、磁性和输运研究等手段研究了边缘几何形状在电子结构中的作用。结果表明，锯齿形边缘产生了对边缘化学细节敏感的非键边缘态，而扶手椅形边缘则产生了对电子稳定性有贡献的电子波干涉.

The electronic structure of nanographene crucially depends on the edge geometry. This is a consequence of the boundary condition of the massless Dirac fermion in physics, while it can be understood on the basis of aromaticity in chemistry. We investigated the role of edge geometry in the electronic structure using STM/STS, AFM, Raman scattering, NEXAFS and magnetic and transport investigations. It is found that nonbonding edge state, which is sensitive to edge chemistry details, is created in the zigzag edges, while electron wave interference contributing to the electronic stability takes place in the armchair edges.