Impurity-assisted tunneling in grapheneM. Titov
Department of Physics, Konstanz University - D-78457 Konstanz, Germany
received 27 March 2007; accepted in final form 18 May 2007; published July 2007
published online 7 June 2007
The electric conductance of a strip of undoped graphene increases in the presence of a disorder potential, which is smooth on atomic scales. The phenomenon is attributed to impurity-assisted resonant tunneling of massless Dirac fermions. Employing the transfer matrix approach we demonstrate the resonant character of the conductivity enhancement in the presence of a single impurity. We also calculate the two-terminal conductivity for the model with one-dimensional fluctuations of disorder potential by a mapping onto a problem of Anderson localization.
73.63.-b - Electronic transport in nanoscale materials and structures.
73.22.-f - Electronic structure of nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals.
72.15.Rn - Localization effects (Anderson or weak localization).
© Europhysics Letters Association 2007