THOMAS FERMI SCREENING CONSTANT FREE

Due to a peculiar suppression of localization effects, electrical conductivity never falls below a certain value (resistivity ПЃmax в‰€ 6.5 kО©) corresponding to the quantum unit of Mott conductance. The striking properties of this material ensue from the peculiar electronic structure which in the ideal honeycomb lattice shows gapless (approximately) linear-spectrum bands with degeneracy points (two per cell) at the corners of the hexagonal Brillouin zone. PACS: 71.10.Ca, 73.61.Le Graphene is a bidimensional structure which has newly attracted the interest of physic community since the recent report on the successful isolation of free-standing carbon monolayers. Early conclusions about Thomas-Fermi screening in graphene are revised.

THOMAS FERMI SCREENING CONSTANT FREE

In the case of a charged sheet, the screened potential presents a tail dependent on the free carrier density whose importance is connected with the local features of the impurity system. Exact and approximated (for qualitative considerations) solutions are presented. A self-consistent field equation in the real space domain is obtained by using a suitable Thomas-Fermi procedure. The in-plane static screening of the field originated by a charge placed in a graphene sheet is investigated.

Thomas fermi screening constant