LOCALIZATION AND FLUCTUATIONS IN THE QUANTUM HALL REGIME

A numerical study is performed on the conductance in quantum wires and their junctions in strong magnetic fields. For the lowest Landau level, the energy and system-size dependence of transmission probabilities and their fluctuations is quite universal and characterized by a single parameter within the numerical accuracy. The critical exponent obtained from the width of the transition region between adjacent quantized plateaus is in good agreement with that of localization of bulk Landau states. For the first excited Landau levels, strong mixing between the edge state of the lowest Landau level and bulk states destroys the universality.