Fizika Nizkikh Temperatur: Volume 45, Number 2 (February 2019), p. 204-209 ( to contents , go back )
Scaling laws under quantum Hall effect for a smooth disorder potential
S.V. Gudina, A.S. Klepikova, V.N. Neverov, N.G. Shelushinina, and M.V. Yakunin
M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 18 S. Kovalevskaya Str., Ekaterinburg 620990, Russia
Received October 3, 2018, published online December 20, 2018
We carried out the analysis of discovered experimental values of the critical parameter κ for the quantum Hall plateau-plateau transitions in modulation-doped GaAs/AlGaAs heterostructures. It turned out that these values are in the main concentrated at the range of 0.5–0.7. We argue that within the theoretical concepts for the large- scale disorder potential, it corresponds to a borderland between quantum tunnelling processes and classical percolation regime. Just, the critical exponent value for the bandwidth of delocalized states, κ = 0.54 ± 0.01, obtained by us for HgTe-based heterostructure with inverted band spectrum, can be associated with a smooth character of impurity potential in our system.
Key words: quantum Hall effect, scaling hypothesis, quantum wells, semiconductors, disorder potential.