Related papers: Triple-top-gate technique for studying the strongl…
Electron-electron (e-e) collisions can impact transport in a variety of surprising and sometimes counterintuitive ways. Despite strong interest, experiments on the subject proved challenging because of the simultaneous presence of different…
We demonstrate the trapping of electrons propagating ballistically at far-above-equilibrium energies in GaAs/AlGaAs heterostructures in high magnetic field. We find low-loss transport along a gate-modified mesa edge in contrast to an…
Recently, a logarithmic decrease of conductivity has been observed in topological insulators at low temperatures, implying a tendency of localization of surface electrons. Here, we report quantum transport experiments on the topological…
Van der Waals materials enable the construction of atomically sharp interfaces between compounds with distinct crystal and electronic properties. This is dramatically exploited in moir\'e systems, where a lattice mismatch or twist between…
Single-layer transition metal dichalcogenide (TMD) WSe2 has recently attracted a lot of attention because it is a 2D semiconductor with a direct band-gap. Due to low doping levels it is intrinsic and shows ambipolar transport. This opens up…
The high-frequency conductivity of Si delta-doped GaAs/AlGaAs heterostructures is studied in the integer quantum Hall effect (QHE) regime, using acoustic methods. Both the real and the imaginary parts of the complex conductivity are…
A top-gated single wall carbon nanotube is used to define three coupled quantum dots in series between two electrodes. The additional electron number on each quantum dot is controlled by top-gate voltages allowing for current measurements…
Unique electronic spin textures in topological states of matter are promising for emerging spin-orbit driven memory and logic technologies. However, there are several challenges related to the enhancement of their performance, electrical…
We observe that in a strongly interacting two-dimensional electron system in ultra-clean SiGe/Si/SiGe quantum wells, the resistivity on the metallic side near the metal-insulator transition increases with decreasing temperature, reaches a…
There is an increasing interest in the electronic properties of few layer graphene as it offers a platform to study electronic interactions because the dispersion of bands can be tuned with number and stacking of layers in combination with…
We measure the frequency dependent capacitance of a gate covering the edge and part of a two-dimensional electron gas in the quantum Hall regime. In applying a positive gate bias, we create a metallic puddle under the gate surrounded by an…
We conduct experimental studies on the electrical transport properties of monolayer graphene directly covered by a few layers of $\rm CrI_3$. We do not observe the expected magnetic exchange coupling in the graphene but instead discover…
Transport properties of single- and two-site mesoscopic quantum Hall (QH) circuits at high transparencies can be described in terms of the lowest-order backscattering processes, enabling a mapping to the boundary sine-Gordon model. We show…
We investigate the gate voltage dependence of capacitance of a system gate - 2D electron gas (C-Vg). The abrupt drop of capacitance at decreasing concentration was found. The possible reasons of this drop, namely inhomogeneity of electron…
We observe nearly vanishing Hall resistances for integer filling factors in a counterflow (CF) experiment on a density balanced 2D bilayer system. Filling factor dependent equilibration lengths demonstrate enhanced 1D coupling via…
Two dimensional electron gases (2DEGs) formed at the interfaces of oxide heterostructures draw considerable interest owing to their unique physics and potential applications. Growing such heterostructures on conventional semiconductors has…
We report on the temperature dependent electron transport in graphene at different carrier densities $n$. Employing an electrolytic gate, we demonstrate that $n$ can be adjusted up to 4$\times10^{14}$cm$^{-2}$ for both electrons and holes.…
In the last six years, Indium selenide (InSe) has appeared as a new van der Waals heterostructure platform which has been extensively studied due to its unique electronic and optical properties. Such as transition metal dichalcogenides…
It has been generally accepted that the threshold structure observed in the oxygen K edge X-ray absorption spectrum in 3d transition metal oxides represents the electronic structure of the 3d transition metal. There is, however, no…
We study, the interplay between topology and electron-electron interactions in the moir\'{e} MoTe\(_2\)/WSe\(_2\) heterobilayer. In our analysis we apply an effective two-band model with complex hoppings that incorporates the Ising-type…