2008/01/30 by E. H. Hwang, S. Das Sarma · 3 citations
Engineering · Materials Science · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Condensed matter physics #Graphene #Graphene research and applications #Impurity #Materials science #Optics #Physics #Quantum and electron transport phenomena #Quantum mechanics #Scattering #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.77.195412
published as Phys. Rev. B 77, 195412 (2008) · 7 pages, 4 figures
arxiv created 2008/01/30 · openalex publication_date 2008/05/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We theoretically calculate and compare the single particle relaxation time (\ensuremathτs) defining the quantum level broadening and the transport scattering time (\ensuremathτt) defining the Drude conductivity in two-dimensional (2D) graphene layers in the presence of screened charged impurity scattering and short-range defect scattering. We find that the ratio \ensuremathτt∕\ensuremathτs strongly increases with increasing kFzi and \ensuremathκ, where kF, zi, and \ensuremathκ are, respectively, the Fermi wave vector, the separation of the substrate charged impurities from the graphene layer, and the background lattice dielectric constant. A critical quantitative comparison of the \ensuremathτt∕\ensuremathτs results for graphene with those for the corresponding modulation-doped semiconductor structures is provided, showing significant differences between these two 2D carrier systems.