Low Temperature Physics: 33, 762 (2007); https://doi.org/10.1063/1.2780170 (5 pages)
Fizika Nizkikh Temperatur: Volume 33, Number 9 (September 2007), p. 1002-1007 ( to contents , go back )
Impurity induced Dirac point smearing in graphene
Yuriy V. Skrypnyk
Kurdyumov Institute of Metal Physics, 36 Vernadsky Ave., Kyiv 03680, Ukraine
Vadim M. Loktev
Bogolyubov Institute for Theoretical Physics, 14-b Metrolohichna Str., Kyiv 03680, Ukraine
Received January 25, 2007
It is shown that in a two-dimensional system with the linear dispersion a resonance is present in the Dirac point vicinity, when the impurity perturbation magnitude exceeds the bandwidth. The corresponding spectrum rearrangement, which follows at a certain critical impurity concentration, results in the square root dependence of the concentration smearing region width on the concentration. If the perturbation magnitude does not exceed the bandwidth, or the critical concentration is not reached, the concentration smearing region width remains exponentially small.
PACS: 71.23.An Theories and models; localized states;
Key words: graphene, Dirac spectrum, impurity, spectrum rearrangement.