Critical Conductance and Its Fluctuations at Integer Hall Plateau Transitions

Under periodic boundary conditions in the transverse direction, we calculate the averaged zero-temperature two-terminal conductance $〈G〉$ and its statistical fluctuation $〈(\delta G{)}^{2n}〉$, for $n\le 4$, at the critical point of integer quantum Hall plateau transitions. We find universal values for $〈G〉=(0.58\pm 0.03)e^2/h$, and $〈(\delta G{)}^{2n}〉=(e^2/h{)}^{2n}{A}_{2n}$, where $A_{2,4,6,8}=0.081\mathrm{}\pm 0.005$, $0.013\pm 0.003$, $0.0026\pm 0.005$, and $(8\pm 2)\times {10}^{-4\mathrm{}}$, respectively. We also determine the leading finite size scaling corrections to these observables, and make comparisons with experiments.