Observations of local electron states on the edges of the circular pits on hydrogen-etched graphite surface by scanning tunneling spectroscopy

Abstract

Scanning tunneling microscopy (STM) and spectroscopy (STS) are used to study electronic states at the edges of the circular pits on the hydrogen-etched graphite surface. The edge surface state revealed by tunneling spectroscopy appears as the maximum of the local density of states (LDOS) in the energy range of 90–250 meV above the Fermi level. The dispersion of the energy state is explained by the band broadening in AB stacked H-terminated graphite. The magnitude of the edge state decreases with the distance from the pit edge as theoretically predicted.