title: Measurement of scattering rate and minimum conductivity in graphene.
abstract: The conductivity of graphene samples with various levels of disorder is investigated for a set of specimens with mobility in the range of 1-20x10(3) cm2/V sec. Comparing the experimental data with the theoretical transport calculations based on charged impurity scattering, we estimate that the impurity concentration in the samples varies from 2-15x10(11) cm(-2). In the low carrier density limit, the conductivity exhibits values in the range of 2-12e2/h, which can be related to the residual density induced by the inhomogeneous charge distribution in the samples. The shape of the conductivity curves indicates that high mobility samples contain some short-range disorder whereas low mobility samples are dominated by long-range scatterers.
authors.affiliation: Department of Physics, Columbia University, New York, New York 10027, USA.
authors.forename: Y-W
authors.initials: YW
authors.lastname: Tan
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: K
authors.initials: K
authors.lastname: Bolotin
authors.forename: Y
authors.initials: Y
authors.lastname: Zhao
authors.forename: S
authors.initials: S
authors.lastname: Adam
authors.forename: E H
authors.initials: EH
authors.lastname: Hwang
authors.forename: S
authors.initials: S
authors.lastname: Das Sarma
authors.forename: H L
authors.initials: HL
authors.lastname: Stormer
authors.forename: P
authors.initials: P
authors.lastname: Kim