Related papers: Reducing disorder in Ge quantum wells by using thi…

Studies of different experimental groups that explore the properties of a two-dimensional electron gas in silicon semiconductor systems ((100) Si metal-oxide-semiconductor field-effect transistors (MOSFETs) and (100) SiGe/Si/SiGe quantum…

We report on quantum-interference measurements in top-gated Hall bars of monolayer graphene epitaxially grown on the Si face of SiC, in which the transition from negative to positive magnetoresistance was achieved varying temperature and…

Utilizing a novel carbon doping source, we prepared two-dimensional hole gases in a symmetric quantum well structure in the GaAs/AlGaAs heterosystem. Low temperature hole mobilities up to 1.2 x 10^6 cm^2/Vs at a density of 2.3 x 10^11 cm^-2…

Evaluation of critical bandstructure and quantum transport parameters in two-dimensional systems is challenging when competition emerges among different energy scales shaping quantum oscillations in a magnetic field. Here we overcome this…

We report on detailed room temperature and low temperature transport properties of double-gate Si MOSFETs with the Si well thickness in the range 7-17 nm. The devices were fabricated on silicon-on-insulator wafers utilizing wafer bonding,…

Si dominates the semiconductor industry material but possesses an abnormally low room temperature hole mobility (505 cm^2/Vs), which is four times lower than that of Diamond and Ge (2000 cm^2/Vs), two adjacent neighbours in the group IV…

The density-dependent mobility of n-type HgTe quantum wells with inverted band ordering has been studied both experimentally and theoretically. While semiconductor heterostructures with a parabolic dispersion exhibit an increase in mobility…

We report on systematic study of transport properties of a 1000-nm HgTe film. Unlike to thinner and strained HgTe films, which are known as high-quality three-dimensional (3D) topological insulators, the film under study is much thicker…

The complex band structure, large spin-orbit induced band splitting, and heavy effective mass of two-dimensional (2D) hole systems hosted in GaAs quantum wells render them rich platforms to study many-body physics and ballistic transport…

We demonstrate dual-gated $p$-type field-effect transistors (FETs) based on few-layer tungsten diselenide (WSe$_2$) using high work-function platinum source/drain contacts, and a hexagonal boron nitride top-gate dielectric. A device…

We fabricate an undoped Ge quantum well under 30 nm Ge0.8Si0.2 shallow barrier with reverse grading technology. The under barrier is deposited by Ge0.8Si0.2 followed by Ge0.9Si0.1 so that the variation of Ge content forms a sharp interface…

Charge noise in the host semiconductor degrades the performance of spin-qubits and poses an obstacle to control large quantum processors. However, it is challenging to engineer the heterogeneous material stack of gate-defined quantum dots…

Issues of Ge hut array formation and growth at low temperatures on the Ge/Si(001) wetting layer are discussed on the basis of explorations performed by high resolution STM and in-situ RHEED. Data of HRTEM studies of multilayer Ge/Si…

Electron spin qubits in Si/SiGe quantum wells are limited by the small and variable energy separation of the conduction band valleys. While sharp quantum well interfaces are pursued to increase the valley splitting energy deterministically,…

We report low-temperature magneto-transport measurements of an undoped Si/SiGe asymmetric double quantum well heterostructure. The density in both layers is tuned independently utilizing a top and a bottom gate, allowing the investigation…

We perform quantum Hall measurements on three types of commercially available modulation doped Si/SiGe heterostructures to determine their suitability for depletion gate defined quantum dot devices. By adjusting the growth parameters, we…

Two-dimensional electron systems (2DESs) confined to the surface of narrowband semiconductors have attracted great interest since they can easily integrate with superconductivity (or ferromagnetism) enabling new possibilities in hybrid…

The electrical characterisation of classical and quantum devices is a critical step in the development cycle of heterogeneous material stacks for semiconductor spin qubits. In the case of silicon, properties such as disorder and energy…

Due to presence of magnetic field gradient needed for coherent spin control, dephasing of single-electron spin qubits in silicon quantum dots is often dominated by $1/f$ charge noise. We investigate theoretically fluctuations of ground…

Gate-tunable high-mobility InSb/In_{1-x}Al_{x}Sb quantum wells (QWs) grown on GaAs substrates are reported. The QW two-dimensional electron gas (2DEG) channel mobility in excess of 200,000 cm^{2}/Vs is measured at T=1.8K. In asymmetrically…