Peak Values of the Longitudinal Conductivity under Integer Quantum Hall Effect Conditions for Sharp and Smooth Chaotic Potentials

The problem of the peak values of the longitudinal conductivity under integer quantum Hall effect conditions is studied. The limiting cases of sharp and smooth chaotic potentials are considered. In the case of a sharp chaotic potential, the first longitudinal conductivity peak (sigma((0))(xx)) obtained by the extrapolation of numerical data to an infinite sample size L -> infinity is (0.55 +/- 0.03)e(2)/h. In the case of a smooth chaotic potential, the peak values of the longitudinal conductivity are independent of the Landau level number and decrease as the chaotic-potential correlation length lambda increases. The results obtained for sharp and smooth chaotic potentials agree with the reported experimental and numerically calculated data.