ELECTRON LOCALIZATION IN A 2-DIMENSIONAL SYSTEM WITH RANDOM MAGNETIC-FLUX

Using a finite-size scaling method, we calculate the localization properties of a disordered two-dimensional electron system in the presence of a random magnetic field. Below a critical energy E(c) all states are localized and the localization length xi diverges when the Fermi energy approaches the critical energy, i.e., xi(E) proportional to \E - E(c)\(-nu). We find that E(c) shifts with the strength of the disorder and the amplitude of the random magnetic field while the critical exponent (nu approximate to 4.5) remains unchanged, indicating universality in this system. Implications on the experiment in the half-filling fractional quantum Hall system are also discussed.