Statistical properties of eigenstates in three-dimensional mesoscopic systems with off-diagonal or diagonal disorder

The statistics of eigenfunction amplitudes are studied in mesoscopic disordered electron systems of finite size. The exact eigenspectrum and eigenstates are obtained by solving numerically Anderson Hamiltonian on a three-dimensional lattice for different strengths of disorder introduced either in the potential on-site energy (diagonal'') or in the hopping integral (off-diagonal’'). The samples are characterized by the exact zero-temperature conductance computed using real-space Green function technique and related Landauer-type formula. The comparison of eigenstate statistics in two models of disorder shows sample-specific details which are not fully taken into account by the conductance, shape of the sample and dimensionality. The wave function amplitude distributions for the states belonging to different transport regimes within the same model are contrasted with each other as well as with universal predictions of random matrix theory valid in the infinite conductance limit.