Scaling and universality of integer quantum Hall plateau-to-plateau transitions -: art. no. 206807

We have investigated the integer quantum Hall plateau-to-plateau transition in two-dimensional electrons confined to AlxGa1-xAs-Al0.33Ga0.67As heterostructures over a broad range of Al concentration x. For x between 0.65% and 1.6%, where the dominant contribution to disorder is from the short-range alloy potential fluctuations, we observe a perfect power-law scaling in the temperature range from 30 mK to 1 K with a critical exponent kappa=0.42 +/- 0.01.