Related papers: Record-quality GaAs two-dimensional hole systems
The resistivity $\rho$ of high mobility dilute 2D holes in GaAs exhibits a peak at a certain temperature $T^*$ in zero magnetic field($B$=0). In the $T>T^*$ regime where d$\rho$/d$T<$0, we observe for the first time both the $\nu=1$ quantum…
Shallow GaAs/InGaAs/GaAs quantum well structures with and without a three monolayer thick AlAs central barrier have been investigated for different well widths and Si doping levels. The transport parameters are determined by resistivity…
We have studied quantum-well-confined holes based on the Luttinger-model description for the valence band of typical semiconductor materials. Even when only the lowest quasi-two-dimensional (quasi-2D) subband is populated, the static spin…
In ultra-high quality two-dimensional (2D) materials the mean free paths of phonons and electrons relative to all mechanisms of scattering can be much greater than a size of a sample. In this case the most intensive type of scattering of…
We report low-dimensional tunneling in an independently contacted vertically coupled quantum wire system. This nanostructure is fabricated in a high quality GaAs/AlGaAs parallel double quantum well heterostructure. Using a novel flip chip…
The integer quantum Hall effect is a well-studied phenomenon at frequencies below about 100 Hz. The plateaus in high-frequency Hall conductivity were experimentally proven to retain up to 33 GHz, but the behavior at higher frequencies has…
Suppressing electron scattering is essential to achieve high-mobility two-dimensional electron systems (2DESs) that are clean enough to probe exotic interaction-driven phenomena. In heterostructures it is common practice to utilize…
Strong spin-orbit interaction characteristic for p-type GaAs systems, makes such systems promising for the realization of spintronic devices. Here we report on transport measurements in nanostructures fabricated on p-type, C-doped GaAs…
Measurements of commensurability oscillations in GaAs/AlGaAs two-dimensional (2D) hole systems grown on GaAs (311)A substrates reveal a remarkable anisotropy: the amplitude of the measured commensurability oscillations along the…
Gate-controllable two dimensional systems with in-plane modulation of properties could serve as highly tunable effective media. Intuitively, such systems may bring novel functionality provided that the period of the lateral modulation is…
The even-denominator fractional quantum Hall states (FQHSs) in half-filled Landau levels are generally believed to host non-Abelian quasiparticles and be of potential use in topological quantum computing. Of particular interest is the…
Transport experiments in high mobility (110) GaAs heterostructures have been performed at very low temperatures 8 mK. At higher Landau-Levels we observe a transport anisotropy that bears some similarity with what is already seen at…
A magnetic field applied parallel to the two-dimensional hole system in the GaAs/AlGaAs heterostructure, which is metallic in the absence of an external magnetic field, can drive the system into insulating at a finite field through a well…
We report resistivity measurements from 0.03 K to 10 K in a dilute high mobility 2D electron system. Using an undoped GaAs/AlGaAs heterojunction in a gated field-effect transistor geometry, a wide range of densities, $0.16 \times 10^{10}…
We report on transport characteristics of field effect two-dimensional electron gases (2DEG) in surface indium antimonide quantum wells. The topmost 5 nm of the 30 nm wide quantum well is doped and shown to promote the formation of…
Separately contacted double layers of a 2d electron - 2d hole gases have been prepared in GaAs separated by thin AlGaAs barriers with thicknesses down to 15 nm. The molecular-beam-epitaxial growth was interrupted just before the barrier in…
The low-temperature conductivity of low-density, high-mobility, two-dimensional hole systems in GaAs was studied. We explicitly show that the metal-insulator transition, observed in these systems, is characterized by a well-defined critical…
Recent magneto-transport experiments on ultra-high mobility 2D electron systems in GaAs/AlGaAs heterostructures have revealed the existence of whole new classes of correlated many-electron states in highly excited Landau levels. These new…
Germanane (GeH) is essentially a hydrogen-terminated Ge analog of graphene with a direct gap (~1.6 eV). Record hole mobility mu_h~67,000 cm2/Vs is found at 15 K for a single allotropic cross-dimensional(D) heterointerface. This is enabled…
We describe the growth of modulation-doped ZnSe/(Zn,Cd)Se quantum wells on (110) GaAs substrates. Unlike the well-known protocol for the epitaxy of ZnSe-based quantum structures on (001) GaAs, we find that the fabrication of quantum well…