LOCALIZATION LENGTH IN A RANDOM MAGNETIC-FIELD

The Kubo formula is used to get the de conductance of a statistical en semble of two-dimensional clusters of the square lattice in the presen ce of random magnetic fluxes. Fluxes traversing lattice plaquettes are distributed uniformly between -1/2 Phi(0) and 1/2 Phi(0) with Phi(0) the flux quantum. The localization length is obtained from the exponen tial decay of the averaged conductance as a function of the cluster si de, Standard results are recovered when this numerical approach is app lied to an Anderson model of diagonal disorder. The localization lengt h of the complex nondiagonal model of disorder remains well below xi = 10(4) in the main part of the band in spite of its exponential increa se near the band edges. [S0163-1829(98)05601-X].