It is known that zigzag graphene edge is able to support edge states: There is a nondispersive single-electron band localized near the zigzag edge. However, it is generally believed that no edge states exist near the unmodified armchair edge, while they do appear if the edge is subjected to suitable modifications (e.g., chemical functionalization). We explicitly present two types of edge modification which support the localized states. Unlike zigzag edge states, which have zero energy and show no dispersion, properties of the armchair localized states depend sensitively on the type of edge modification. Under suitable conditions they demonstrate pronounced dispersion. While the zigzag edge state wave function decays monotonously when we move away from the edge, the armchair edge state wave function shows nonmonotonous decay. Such states may be observed in scanning tunneling spectroscopy experimentally.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 16 Dec 2013|