Critical properties of the metal-insulator transition in anisotropic systems

Frank Milde, Rudolf A. Römer, Michael Schreiber, Ville Uski

Published 1999-11-03Version 1

We study the three-dimensional Anderson model of localization with anisotropic hopping, i.e., weakly coupled chains and weakly coupled planes. In our extensive numerical study we identify and characterize the metal-insulator transition by means of the transfer-matrix method. The values of the critical disorder $W_c$ obtained are consistent with results of previous studies, including multifractal analysis of the wave functions and energy level statistics. $W_c$ decreases from its isotropic value with a power law as a function of anisotropy. Using high accuracy data for large system sizes we estimate the critical exponent as $\nu=1.62\pm0.07$. This is in agreement with its value in the isotropic case and in other models of the orthogonal universality class.