Tunneling Conductance in Correlated Graphenes

摘要

Line shape of tunneling conductance observed for a correlated graphene is studied theoretically. We focus on the line shape of scanning tunneling spec-troscopy (STS) for a doped graphene flake. We obtain the STS line shape in terms of elastic tunneling of a Kondo singlet through the coherent tunneling levels that are formed due to two reservoirs within coherent regime. The resonant tunneling of a singlet through this coherent tunneling level causes the abrupt increase in tunneling conductance at a finite bias. The shifted position of Dirac point from the Fermi level is responsible for making the line shape of tunneling conductance asymmetric.