SCALING PROPERTIES OF CONDUCTANCE AT INTEGER QUANTUM HALL PLATEAU TRANSITIONS

We investigate the scaling properties of zero-temperature conductances at integer quantum Hall plateau transitions in the lowest Landau band of a two-dimensional tight-binding model. Scaling is obeyed for all e nergy and system sizes with critical exponent v approximate to 7/3. Th e arithmetic average of the conductance at the localization-delocaliza tion critical point is found to be [G](c) = 0.506e(2)/h, in agreement with the universal longitudinal conductance [sigma(xx)] = 1/2e(2)/h pr edicted by an analytical theory. The probability distribution of the c onductance at the critical point is broad with a dip at small G.