Volume 79, Number 1, July 2007
Article Number 17004
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 07 June 2007
EPL, 79 (2007) 17004
DOI: 10.1209/0295-5075/79/17004

Impurity-assisted tunneling in graphene

M. 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