Non-universal scaling in the integer quantum Hall effect regime in two-dimensional electron gas in InGaAs/InP heterostructures

摘要

We report on temperature scaling experiments on the integer quantum Hall effect plateau-to-plateau transitions as well as on the i = 1 plateau-to-insulating phase transitions in two-dimensional electron gas in In_(0.53)Ga_(0.47)As/InP modulation-doped heterostructures. We have measured the longitudinal ρ_(xx) and Hall ρ_(xy) resistivities as a function of magnetic field in the temperature range 40 mK - 4.2 K. It was found that for both types of transitions the scaling exponent has the same value κ ≈ 0.6-0.7. The scaling exponent obtained in our experiments is significantly greater than κ = 0.42, the value generally considered to be universal.