Magnetoconductivity of a two-dimensional electron gas in Al0.3Ga0.7As/Ga1-xINxAs/GaAs pseudomorphic heterostructures in the quantum Hall regime

The transverse magnetoconductivity xx of a two-dimensional electron gas (2D EG) in selectively doped Al0.3Ga0.7As/ Ga1-xInxAs/GaAs pseudomorphic structures is shown to behave very differently from that of the Al0.3Ga0.7As/GaAs structures in the quantum Hall regime. Well-defined peaks of transverse conductivity xx corresponding to each Landau level were observed and their peak heights increased with the increase of InAs composition. Also, the peak height of xx increases with the Landau number N in the pseudomorphic structure, especially for samples with x0.13 xx varies in proportional to N+(1/2, whereas it remains almost unchanged when N increased in the AlyGa1-yAs/GaAs structures. The behavior of xx for the pseudomorphic structure is very similar to that of the 2D EG formed in the inversion layer of the Si metal-oxide-semiconductor field-effect transistor. The observed difference between the pseudomorphic structure and the AlyGa1-yAs/GaAs heterostructure is interpreted in terms of the change in the dominant scattering mechanism, i.e., the short-range cluster scattering in the former, and the long-range scattering in the latter.