Minimal conductivity in graphene: Interaction corrections and ultraviolet anomalyE. G. Mishchenko
Department of Physics, University of Utah - Salt Lake City, UT 84112, USA
received 26 March 2008; accepted in final form 7 May 2008; published July 2008
published online 12 June 2008
Conductivity of a disorder-free intrinsic graphene is studied to the first order in the long-range Coulomb interaction and is found to be =0(1 + 0.01g), where g is the dimensionless ("fine structure") coupling constant. The calculations are performed using three different methods: i) electron polarization function, ii) Kubo formula for the conductivity, iii) quantum transport equation. Surprisingly, these methods yield different results unless a proper ultraviolet cut-off procedure is implemented, which requires that the interaction potential in the effective Dirac Hamiltonian is cut-off at small distances (large momenta).
73.23.-b - Electronic transport in mesoscopic systems.
73.25.+i - Surface conductivity and carrier phenomena.
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