Effect of disorder on the groundstate properties of graphene.pdf

Effect of disorder on the ground-state properties of graphene R. Asgari,1 M. M. Vazifeh,2 M. R. Ramezanali,2 E. Davoudi,3 and B. Tanatar4 1School of Physics, Institute for Studies in Theoretical Physics and Mathematics, 19395-5531 Tehran, Iran 2Department of Physics, Sharif university of Technology, Tehran 11155-9161, Iran 3Department of Physics, Islamic Azad university , Tehran 14168-94351, Iran 4Department of Physics, Bilkent University, Bilkent, 06800 Ankara, Turkey We calculate the ground-state energy of Dirac electrons in graphene in the presence of disorder. We 8 take randomly distributed charged impurities at a fixed distance from the graphene sheet and surface 0 fluctuations (ripples) as the main scattering mechanisms. Mode-coupling approach to scattering rate 0 and random-phase approximation for ground-state energy incorporating the many-body interactions 2 and the disorder effects yields good agreement with experimental inverse compressibility. b PACS numbers: 73.63.-b 72.10.-d 71.55.-i 71.10.-w e F 5 I. INTRODUCTION isotropic and have a single circular Fermi surface. The strength of interaction effects in a conventional 2DEG ] increases with decreasing carrier density. At low den- l Two-dimensional crystals of Carbon atoms (graphene) l 1 sities, the quasiparticle weight Z is small, the velocity