ANDERSON LOCALIZATION FOR SUBLATTICE MODELS

A new universality class for the Anderson-localization behaviour is es tablished. It is represented by a particular class of the Anderson mod el where all random variables or regular matrix transfer elements conn ect only points of different sublattices. For the band centre an effec tive field theory based on the replica trick with manifold GL(4m, C)/U (4m) is derived. From an epsilon expansion a trivial beta function ind icating extended states at the band centre in two dimensions is obtain ed. Due to the nonvanishing zeta function the density of states is enh anced for d > 2 and diverges as d approaches 2. For nonzero energies t he sublattice restriction does not modify the symmetry group. The ener gy dependence of several quantities related to one- and two-particle G reen functions is given in a crude approximation.