Electronic and Transport Properties of Graphene Systems
|Date/Time:||Friday, 09 Apr 2010 from 2:10 pm to 3:00 pm|
|Channel:||Condensed Matter Physics|
Graphene, a single atomic layer of carbon atoms arranged in a honeycomb lattice, is a unique system containing two-dimensional electrons with a vanishing effective mass for the electrons and holes near the Fermi level. A critical step in developing graphene-based nanoelectronics is to create a band gap in the material, which may be accomplished through chemical functionalization. I will describe our systematic investigation of the oxidation effect on the structural and electronic properties of graphene based on first-principles calculations. I will also present a first-principles study of the conductance through graphene suspended between Al contacts as a function of junction length, width, and orientation. The charge transfer at the leads and into the freestanding section gives rise to an electron-hole asymmetry in the conductance. We obtain the potential profile along a junction caused by doping and provide parameters for effective model calculations of the junction conductance with weakly interacting metallic leads.