Electron scattering in graphene by a correlated charged impurities

ORAL

Abstract

We study charge transport in graphene with correlated charged impurities. Potassium is deposited on graphene in ultra-high vacuum at temperatures below 20 K, and the conductivity of graphene is measured as a function of carrier density in situ. Upon heating, the potassium ions order due to repulsive interactions, resulting in significant improvement of device mobility due to decrease of long range scattering. The charge density dependence of the conductivity becomes increasingly non-linear with increase of annealing temperature of the potassium/graphene. We find the experimental carrier-density-dependent conductivity in good agreement with a model of correlated charged impurities including a Gaussian-broadened structure factor at a finite wavevector corresponding to the potassium lattice.

*This work is supported by ONR-MURI and the UMD NSF MRSEC grant no. DMR 05-20471

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Authors

  • Michael Fuhrer

    • University of Maryland
    • Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742-4111, USA
    • Center for Nanophysics and Advanced Materials, University of Maryland, College Park
    • Center for Nanophysics and Advanced Materials, Univesity of Maryland
    • Materials Research Science and Engineering Center and Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland
    • Dept. of Physics, Materials Research Science and Engineering Center and Center for Nanophysics and Advanced Materials, Univ. of Maryland, College Park

  • Jun Yan

    • Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742-4111, USA
    • Center for Nanophysics and Advanced Materials, Univesity of Maryland

  • Jianhao Chen

    • Center for Nanophysics and Advanced Materials, Univesity of Maryland

  • Shudong Xiao

    • Center for Nanophysics and Advanced Materials, Univesity of Maryland