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Doped graphene: the interplay between localization and frustration due to the underlying triangular symmetry
J E Barrios-Vargas1, Gerardo G Naumis
1Departamento de Física-Química, Instituto de Física, Universidad Nacional Autónoma de México (UNAM), México DF, México.
Abstract:
An intuitive explanation of the increase in localization observed near the Dirac point in doped graphene is presented. To do this, we renormalize the tight binding Hamiltonians in such a way that the honeycomb lattice maps into a triangular one. Then, we investigate the frustration effects that emerge in this Hamiltonian. In this doped triangular lattice, the eigenstates have a bonding and antibonding contribution near the Dirac point, and thus there is a kind of Lifshitz tail. The increase in frustration is related to an increase in localization, since the number of frustrated bonds decreases with disorder, while the frustration contribution raises.
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