Related papers: Design rules for modulation-doped AlAs quantum wel…
High-quality C-doped p-type AlGaAs heterostructures with mobilities exceeding 150 000 cm$^2$/Vs are investigated by low-temperature magnetotransport experiments. We find features of the fractional quantum Hall effect as well as a highly…
High mobility, strong spin-orbit coupling, and large Land\'e g-factor make the two-dimensional electron gas (2DEG) in InAs quantum wells grown on nearly-lattice-matched GaSb substrates an attractive platform for mesoscopic quantum transport…
Bilayer two-dimensional electron systems formed by a thin barrier in the GaAs buffer of a standard heterostructure were investigated by magnetotransport measurements. In magnetic fields oriented parallel to the electron layers, the…
Low energy excitations of a two-dimensional electron gas (2DEG) in modulation-doped multiple (ten) quantum wells (QWs) was studied using far-infrared magneto-transmission technique at liquid helium temperatures. A large distance between…
We demonstrate the development of a double quantum dot with an integrated charge sensor fabricated in undoped GaAs/AlGaAs heterostructures using a double top-gated design. Based on the evaluation of the integrated charge sensor, the double…
We have studied a series of InAs/GaSb coupled quantum wells using magneto-infrared spectroscopy for high magnetic fields up to 33T within temperatures ranging from 4K to 45K in both Faraday and tilted field geometries. This type of coupled…
Transport properties of GaAs/{\delta}<Mn>/GaAs/In\timesGa1-\timesAs/GaAs structures containing InxGa1-xAs (\times {\approx} 0.2) quantum well (QW) and Mn delta layer (DL) with relatively high, about one Mn monolayer (ML) content, are…
In case of a of the heterostructure n-GaAs/AlGaAs with sheet density $n=2 \times 10^{11}$cm$^{-2}$ and mobility $\mu \approx 2 \times 10^6$ cm$^2$/V$\cdot$s with integer and fractional quantum Hall effect (IQHE and FQHE, respectively) we…
We report an experimental investigation of fractional quantum Hall effect (FQHE) at the even-denominator Landau level filling factor $\nu$ = 1/2 in very high quality wide GaAs quantum wells, and at very high magnetic fields up to 45 T. The…
We report experimental results on a quantum point contact (QPC) device formed in a wide AlAs quantum well where the two-dimensional electrons occupy two in-plane valleys with elliptical Fermi contours. To probe the closely-spaced,…
We describe a technique to fabricate closely spaced electron-hole bilayers in GaAs-AlGaAs heterostructures. Our technique incorporates a novel method for making shallow contacts to a low density ($<10^{11}cm^{-2}$) 2-dimensional electron…
We perform detailed magnetotransport studies on two-dimensional electron gases (2DEGs) formed in undoped Si/SiGe heterostructures in order to identify the electron mobility limiting mechanisms in this increasingly important materials…
In a semiconductor-based double quantum well (QW) coupled to a degree of freedom with an internal dynamics, we demonstrate that the electronic motion is controllable within femtoseconds by applying appropriately shaped electromagnetic…
We have fabricated AlGaAs/GaAs heterostructure devices in which the conduction channel can be populated with either electrons or holes simply by changing the polarity of a gate bias. The heterostructures are entirely undoped, and carriers…
The growth-diection quantization of confined electron gas in a GaAs/AlGaAs based quantum well structure is obtained in the Kohn-Sham iterative computational scheme. The longitudinal conductance at low temperatures, in the presence of…
Motivated by recent breakthrough in molecular beam epitaxy of GaAs/AlGaAs quantum wells [Y. J. Chung \textit{et al.}, Nature Materials \textbf{20}, 632 (2021)], we examine contributions to mobility and quantum mobility from various…
Magnetotransport properties of a pseudomorphic GaAs/Ga0.8In0.2As/Ga0.75Al0.25As heterostructure are investigated in pulsed magnetic fields up to 50 T and at temperatures of T=1.4 K and 4.2 K. The structure studied consists of a Si…
Transitions among quantum Hall plateaux share a suite of remarkable experimental features, such as semi-circle laws and duality relations, whose accuracy and robustness are difficult to explain directly in terms of the detailed dynamics of…
Gate-defined quantum dots in gallium arsenide (GaAs) have been used extensively for pioneering spin qubit devices due to the relative simplicity of fabrication and favourable electronic properties such as a single conduction band valley, a…
We report the magnetoresistance characteristics of one-dimensional electrons confined in a single InAs quantum well sandwiched between AlSb barriers. As a result of a novel nanofabrication scheme that utilizes a 3nm-shallow wet chemical…