Numerical study of the conductivity of graphene monolayer within the   effective field theory approach
  We report on the direct numerical measurements of the conductivity of graphene monolayer. Our numerical simulations are performed in the effective lattice field theory with noncompact 3 + 1-dimensional Abelian lattice gauge fields and 2 + 1-dimensional staggered lattice fermions. The conductivity is obtained from the Green-Kubo relations using the Maximum Entropy Method. We find that in a phase with spontaneously broken sublattice symmetry the conductivity rapidly decreases. For the largest value of the coupling constant used in our simulations g = 4.5, the DC conductivity is less than the DC conductivity in the weak-coupling phase (at g < 3.5) by at least three orders of magnitude. 
P. V. Buividovich, E. V. Luschevskaya, O. V. Pavlovsky, M. I.   Polikarpov and M. V. Ulybyshev
cond-mat.str-el hep-lat