相关论文: AC and DC Conductivities in an n-GaAs/AlAs Heteros…

We study the electron transport through a quantum wire under the influence of external time-dependent gate voltages. The wire is modelled by a tight-binding Hamiltonian for which we obtain the current from the corresponding transmission.…

Discussed in the present study are details of the behavior of low-frequency "acoustic" ($ac$) modes in the spectrum of edge magnetoplasma oscillations in axially symmetric degenerate 2D electron systems where electron density distribution…

The results of systematic experimental studies of quantum oscillations of resistivity, Hall coefficient and capacitance in GaAs and In$_x$Ga$_{1-x}$As quantum wells (QWs) with a simple electron spectrum and HgTe QWs with a complicated…

We show that the study of conductivity nonlinearity gives a possibility to determine the condition when the diffusion conductivity changes to the hopping one with increasing disorder. It is experimentally shown that the conductivity of…

Dense ($n=4 \times 10^{11}$ cm$^{-2}$) arrays of Ge quantum dots in Si host were studied using attenuation of surface acoustic waves (SAWs) propagating along the surface of a piezoelectric crystal located near the sample. The SAW…

The temperature driven flow lines of the Hall and dissipative magnetoconductance data (\sigma_{xy},\sigma_{xx}) are studied in the fractional quantum Hall regime for a 2D electron system in GaAs/Al_{x}Ga_{1-x}As heterostructures. The flow…

The Hall conductance $\sigma_{xy}$ of two-dimensional {\it lattice} electrons with random potential is investigated. The change of $\sigma_{xy}$ due to randomness is focused on. It is a quantum phase transition where the {\it sum rule} of…

In recent years, there is an increasing interest in transport phenomena that are fundamentally linked to the presence of multiple bands. In this thesis, we develop, discuss, and apply a theory of the electrical conductivity that includes…

We analyze here the behavior of the Hall conductivity $\sigma_{xy}$ near a $z=2$ insulator-superconductor quantum critical point in a perpendicular magnetic field. We show that the form of the conductivity is sensitive to the presence of…

An analytic theory is developed for the diagonal conductivity $\sigma_{xx}$ of a 2D conductor which takes account of the localized states in the broaden Landau levels. In the low-field region $\sigma_{xx}$ display the Shubnikov-de Haas…

Electron-electron interactions give rise to the correction, \delta\sigma^{int}(\omega), to the ac magnetoconductivity, \sigma(\omega), of a clean 2D electron gas that is periodic in \omega_c^{-1}, where \omega_c is the cyclotron frequency.…

The effective g-factor of 2D holes in modulation doped \mbox{p-SiGe/Ge/SiGe} structures was studied. The AC conductivity of samples with hole densities from $3.9 \times 10^{11}$~to $6.2 \times 10^{11}~\text{cm}^{-2}$ was measured in…

We calculate using the Boltzmann transport theory the density dependent mobility of two-dimensional (2D) electrons in GaAs, SiGe and AlAs quantum wells as well as of 2D holes in GaAs quantum wells. The goal is to precisely understand the…

We report low-field magnetotransport data in two-dimensional hole systems in GaAs/AlGaAs heterostructures and quantum wells, in a large density range, $2.5 \times 10^{10} \leq p \leq 4.0 \times 10^{11}$ cm$^{-2}$, with primary focus on…

The interaction correction to the conductivity of 2D hole gas in strained GaAs/In$_x$Ga$_{1-x}$As/GaAs quantum well structures was studied. It is shown that the Zeeman splitting, spin relaxation and ballistic contribution should be taking…

We have investigated the magnetoresistance of strongly asymmetric double-well structures formed by a thin AlGaAs barrier grown far from the interface in the GaAs buffer of standard heterostructures. In magnetic fields oriented parallel to…

We measure the longitudinal conductivity $\sigma_{xx}$ at frequencies $1.246 {\rm GHz} \le f \le 10.05$ GHz over a range of temperatures $235 {\rm mK} \le T \le 4.2$ K with particular emphasis on the Quantum Hall plateaus. We find that…

The Zeeman splitting and the underlying value of the g-factor for conduction band electrons in GaAs/Al_xGa_{1-x}As quantum wells have been measured by spin-beat spectroscopy based on a time-resolved Kerr rotation technique. The experimental…

A two-dimensional quantum Hall system is studied for a wide class of potentials including single-body random potentials and repulsive electron-electron interactions. We assume that there exists a non-zero excitation gap above the ground…

The current in response to a bias in certain two-dimensional electron gas (2DEG), can have a nonzero transverse component under a finite magnetic field applied in the plane where electrons are confined. This phenomenon known as planar Hall…