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 energy and system sizes with critical exponent $\nu \approx \frac{7}{3}$. The arithmetic average of the conductance at the localization-delocalization critical point is found to be $〈G{〉}_c{=0.506e}^2/h$, in agreement with the universal longitudinal conductance $〈{\sigma }_{\mathrm{xx}}〉=\frac{1}{2}{e}^2/h$ predicted by an analytical theory. The probability distribution of the conductance at the critical point is broad with a dip at small $G$.