LOCALIZATION PROPERTIES OF QUASI-ONE-DIMENSIONAL CONDUCTOR NETWORKS IN A RANDOM MAGNETIC-FIELD

We investigate the localization of electrons on a ladder-shaped quasi- one-dimensional network of clean wires, with a quenched random magneti c flux across each of its square plaquettes. In the weak-disorder regi me, the localization length xi is much larger than the side of the pla quettes. Using perturbative analytic techniques, we derive scaling law s of the form xi is similar to 1/w(alpha), with w being the width of m agnetic disorder. The critical exponent a assumes different values in various energy ranges: alpha = 4 when only one channel is open, alpha = 2 when both channels are open, alpha = 1 around external and interna l band edges. The corresponding scaling functions and amplitudes are a ccurately determined by numerical simulations. Magnetic disorder and p otential disorder thus pertain to different universality classes.