I. Yu. Smirnov

High-frequency hopping conductivity in the quantum Hall effect regime: Acoustical studies

The high-frequency conductivity of Si

Large magnetoresistance of a dilute p-Si/SiGe/Si quantum well in a parallel magnetic field

\ensuremath{\delta}

Acoustoelectric effects in very high-mobility p-SiGe/Ge/SiGe heterostructure at low temperatures in high magnetic fields

-doped GaAs/AlGaAs heterostructures is studied in the integer quantum Hall effect (QHE) regime, using acoustic methods. Both the real and the imaginary parts of the complex conductivity are determined from the experimentally observed magnetic field and temperature dependencies of the velocity and the attenuation of a surface acoustic wave. It is demonstrated that in structures with carrier density

Acoustoelectric effects in very high-mobility p-SiGe/Ge/SiGe heterostructure

(1.3\ensuremath{-}2.8)\ifmmode\times\else\texttimes\fi{}{10}^{11}{\mathrm{cm}}^{\ensuremath{-}2}

Melting of Wigner crystal in high-mobility n -GaAs/AlGaAs heterostructures at filling factors 0.18 > ν > 0.125 : Acoustic studies

and mobility

Contactless measurement of alternating current conductance in quantum Hall structures

(1\ensuremath{-}2)\ifmmode\times\else\texttimes\fi{}{10}^{5}{\mathrm{cm}}^{2}/\mathrm{V}\mathrm{}\mathrm{s}

Nonlinear high-frequency hopping conduction in two-dimensional arrays of Ge-in-Si quantum dots: Acoustic methods

the mechanism of low-temperature conductance near the QHE plateau centers is hopping. It is also shown that at magnetic fields corresponding to filling factors 2 and 4, the doped Si

Acoustic studies of ac conductivity mechanisms in n-GaAs/Al_{x}Ga_{1-x}As in the integer and fractional quantum Hall effect regime

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Magnetoresistivity and acoustoelectronic effects in a tilted magnetic field in p-Si/SiGe/Si structures with an anisotropic g factor

layer efficiently shunts the conductance in the two-dimensional electron gas (2DEG) channel. A method to separate the two contributions to the real part of the conductivity is developed, and the localization length in the 2DEG channel is estimated within the context of a nearest-neighbor hopping model.

High-frequency transport in p -type Si ∕ Si 0.87 Ge 0.13 heterostructures studied with surface acoustic waves in the quantum Hall regime

We report the results of an experimental study of the magnetoresistance rho(xx) in two samples of p-Si/SiGe/Si with low carrier concentrations p=8.2x10(10) cm(-2) and p=2x10(11) cm(-2). The research was performed in the temperature range of 0.3-2 K in the magnetic fields of up to 18 T, parallel to the two-dimensional (2D) channel plane at two orientations of the in-plane magnetic field B-parallel to against the current I: B-parallel to perpendicular to I and B-parallel to parallel to I. In the sample with the lowest density in the magnetic field range of 0-7.2 T, the temperature dependence of rho(xx) demonstrates the metallic characteristics (d rho(xx)/dT>0). However, at B-parallel to=7.2 T the derivative d rho(xx)/dT reverses the sign. Moreover, the resistance depends on the current orientation with respect to the in-plane magnetic field. At B-parallel to congruent to 13 T there is a transition from the dependence ln(Delta rho(xx)/rho(0))proportional to B-parallel to(2) to the dependence ln(Delta rho(xx)/rho(0))proportional to B-parallel to. The observed effects can be explained by the influence of the in-plane magnetic field on the orbital motion of the charge carriers in the quasi-2D system.