Nonlinearity of Acoustic Effects and High-Frequency Electrical Conductivity in GaAs/AlGaAs Heterostructures under Conditions of the Integer Quantum Hall Effect

Abstract

The absorption coefficient for surface acoustic wave $\Gamma$ and variation in the wave velocity $\Delta V/V$ were measured in GaAs/AlGaAs heterostructures; the above quantities are related to interaction of the wave with two-dimensional electron gas and depend nonlinearly on the power of the wave. Measurements were performed under conditions of the integer quantum Hall effect (IQHE), in which case the two-dimensional electron gas was localized in a random fluctuation potential of impurities. The dependences of the components ${\sigma }_1(E)$ and ${\sigma }_2(E)$ of high-frequency conductivity $\sigma ={\sigma }_1-i{\sigma }_2$ on the electric field of the surface wave were determined. In the range of the conductivity obeying the Arrhenius law (${\sigma }_1\gg {\sigma }_2$), the results obtained are interpreted in terms of the Shklovskii theory of nonlinear percolation-based conductivity, which makes it possible to estimate the magnitude of the fluctuation potential of impurities. The dependences ${\sigma }_1(E)$ and ${\sigma }_2(E)$ in the range of high-frequency hopping electrical conductivity, in which case (${\sigma }_1\ll {\sigma }_2$) and the theory of nonlinearities has not been yet developed, are reported.

RevTeX; 7 pages + 5 eps figs

References in corpus (2)

• Phonon Emission from a 2D Electron Gas: Evidence of Transition to the Hydrodynamic Regime
• Electronic transport and the localization length in the quantum Hall effect

Cited by in corpus (3)

• Melting of Wigner crystal in high-mobility $n$-GaAs/AlGaAs heterostructures at filling factors $0.18>\nu >0.125$: Acoustic studies
• Magnetotransport in low-density $p$-Si/SiGe heterostructures: From metal through hopping insulator to Wigner glass
• Nonlinear acoustic and microwave absorption in disordered semiconductors