2D massless QED Hall half-integer conductivity and graphene
  Starting from the photon self-energy tensor in a magnetized medium, the 3D complete antisymmetric form of the conductivity tensor is found in the static limit of a fermion system $C$ non-invariant under fermion-antifermion exchange. The massless relativistic 2D fermion limit in QED is derived by using the compactification along the dimension parallel to the magnetic field. In the static limit and at zero temperature the main features of quantum Hall effect (QHE) are obtained: the half-integer QHE and the minimum value proportional to $e^2/h$ for the Hall conductivity . For typical values of graphene the plateaus of the Hall conductivity are also reproduced. 
A. P\'erez Mart\'inez, E. Rodriguez Querts, H. P\'erez Rojas, R.   Gaitan, S. Rodriguez Romo
cond-mat.mes-hall hep-ph