Related papers: The nonlinear effects in 2DEG conductivity investi…
The propagation of a surface acoustic wave (SAW) on GaAs/AlGaAs heterostructures is studied in the case where the two-dimensional electron gas (2DEG) is subject to a strong magnetic field and a smooth random potential with correlation…
When a surface acoustic wave (SAW) is coupled piezoelectrically to a two dimensional electron gas (2DEG), a velocity shift and attenuation of the SAW are induced that reflect the conductivity of the 2DEG. This paper considers the case of a…
The heating of a two-dimensional electron gas by an rf electric field generated by a surface acoustic wave, which can be described by an electron temperature $T_e$, has been investigated. It is shown that the energy balance of the electron…
The transport relaxation rate 1/tau of a two-dimensional electron gas due to scattering by thermally excited surface acoustic phonons is calculated. The temperature dependence of 1/tau is found to be linear in T for high temperatures, but…
The absorption of bulk acoustic phonons in a two-dimensional (2D) GaAs/AlGaAs heterostructure is studied (in the clean limit) where the 2D electron-gas (2DEG), being in an odd-integer quantum-Hall state, is in fact a spin dielectric. Of the…
Measurement results of the acoustoelectric effects (surface acoustic waves (SAW) attenuation and velocity) in a high-mobility $p$-SiGe/Ge/SiGe structure are presented. The structure was LEPECVD grown with a two dimensional (2D) channel…
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…
The contactless Surface Acoustic Wave (SAW) technique was implemented to probe the high-frequency (ac) conductivity in a high-mobility $p$-SiGe/Ge/SiGe structure in the integer quantum Hall (IQHE) regime. The structure was grown by…
We study the acousto-electric (AE) effect generated by surface acoustic waves (SAW) in a high mobility 2D electron gas (2DEG) with isotropic and especially small-angle impurity scattering. In both cases the acousto-electric effect exhibits…
The surface acoustic wave (SAWs) attenuation coefficient $\Gamma$ and the velocity change $\Delta V /V$ were measured for $p$-type Si/SiGe heterostructures in the temperature range 0.7 - 1.6 K as a function of external magnetic field $H$ up…
We study theoretically the piezoelectric interaction of a surface acoustic wave (SAW) with a two-dimensional electron gas confined to an isolated quantum dot. The electron motion in the dot is diffusive. The electron-electron interaction is…
The absorption and variation of the velocity of a surface acoustic wave of frequency $f$= 30 MHz interacting with two-dimensional electrons are investigated in GaAs/AlGaAs heterostructures with an electron density $n=(1.3 - 2.8) \times…
The absorption coefficient for surface acoustic waves in a piezoelectric insulator in contact with a GaAs/AlGaAs heterostructure (with two-dimensional electron mobility $\mu= 1.3\times 10^5 cm^2/V\cdot s)$ at T=4.2K) via a small gap has…
Electrically detected electron spin resonance (EDESR) signals were acquired as a function of temperature in the 0.3-4.2 K temperature range in a AlGaAs/GaAs multiple quantum well sample at the filling factor at 5.7 T. In the particular…
We have measured the surface acoustic wave velocity shift in a GaAs/AlGaAs heterostructure containing a two-dimensional electron system (2DES) in a low-density regime ($<$ $10^{10}$ cm$^{-2}$) at zero magnetic field. The interaction of the…
We investigate the propagation of a piezoelectric surface acoustic wave (SAW) across a GaAs/Al$_X$Ga$_{1-X}$As heterostructure surface, on which there is fixed a metallic split-gate. Our method is based on a finite element formulation of…
Ohmic contacts to a two-dimensional electron gas (2DEG) in GaAs/AlGaAs heterostructures are often realized by annealing of AuGe/Ni/Au that is deposited on its surface. We studied how the quality of this type of ohmic contact depends on the…
When a surface acoustic wave propagates on the surface of a GaAs semiconductor, coupling between electrons in the two-dimensional electron gas beneath the interface and the elastic host crystal through piezoelectric interaction will…
We present measurements of the energy relaxation length scale $\ell$ in two-dimensional electron gases (2DEGs). A temperature gradient is established in the 2DEG by means of a heating current, and then the elevated electron temperature…
We present measurements of the cooling length $\ell_E$ for hot electrons in a GaAs-based high mobility two-dimensional electron gas (2DEG). The thermal measurements are performed on a long 60 $\mu$m-wide channel, which is Joule-heated at…