Issue
EPL
Volume 83, Number 1, July 2008
Article Number 17005
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/83/17005
Published online 12 June 2008
EPL, 83 (2008) 17005
DOI: 10.1209/0295-5075/83/17005

Minimal conductivity in graphene: Interaction corrections and ultraviolet anomaly

E. G. Mishchenko

Department of Physics, University of Utah - Salt Lake City, UT 84112, USA

mishch@physics.utah.edu

received 26 March 2008; accepted in final form 7 May 2008; published July 2008
published online 12 June 2008

Abstract
Conductivity of a disorder-free intrinsic graphene is studied to the first order in the long-range Coulomb interaction and is found to be $\sigma$ =$\sigma$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).

PACS
73.23.-b - Electronic transport in mesoscopic systems.
73.25.+i - Surface conductivity and carrier phenomena.

© EPLA 2008