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 magnetic flux across each of its square plaquettes. In the weak-disorder regime, the localization length xi is much larger than the side of the plaquettes. Using perturbative analytic techniques, we derive scaling laws of the form xi is similar to 1/w(alpha), with w being the width of magnetic 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 internal band edges. The corresponding scaling functions and amplitudes are accurately determined by numerical simulations. Magnetic disorder and potential disorder thus pertain to different universality classes.