Anderson localization of two-dimensional Dirac fermions: a perturbative   approach
  Anderson localization is studied for two-dimensional Dirac fermions in the presence of strong random scattering. Averaging with respect to the latter leads to a graphical representation of the correlation function with entangled random walks and three-vertices which connect three different types of propagators. This approach indicates Anderson localization along a semi-infinite line, where the localization length is inversely proportional to the scattering rate. 
K. Ziegler
cond-mat.dis-nn