Related papers: Field effect induced mesoscopic devices in deplete…
Measuring carrier mobility as a function of the carrier density in semiconductors using Hall effect is the gold standard for quantifying scattering mechanisms. However, for nanostructures, the Hall effect is not applicable, and the density…
Up to know all the experimental results concerning the integer and fractional quantum Hall effect are related to semiconductor heterostructures (and more recently with graphene). The common characteristic of all these systems is the…
We report a persistent increase or decrease in the two-dimensional electron density of AlAs or GaAs quantum wells flanked by AlGaAs barriers, brought about by illuminating the samples at T ~ 4 K while simultaneously applying a voltage bias…
The ability to control electronic properties of a material by externally applied voltage is at the heart of modern electronics. In many cases, it is the so-called electric field effect that allows one to vary the carrier concentration in a…
Interactions between mesoscopic devices induced by interface acoustic phonons propagating in the plane of a two-dimensional electron system (2DES) are investigated by phonon-spectroscopy. In our experiments ballistic electrons injected from…
We theoretically investigate the orbital effects of an in-plane magnetic field on the spectrum of a quantum dot embedded in a two-dimensional electron gas (2DEG). We derive an effective two-dimensional Hamiltonian where these effects enter…
We report measurements and calculations of the spin-subband depopulation, induced by a parallel magnetic field, of dilute GaAs two-dimensional (2D) hole systems. The results reveal that the shape of the confining potential dramatically…
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 have fabricated ambipolar transistors on chemically prepared hydrogen-terminated Si(111) surfaces, in which a two-dimensional electron system (2DES) or a two-dimensional hole system (2DHS) can be populated in the same conduction channel…
With an eye towards next-generation, smart, micro/nanofluidic devices, capable of responding to external stimuli or changes in environment, we demonstrate a means to achieve dynamic control of the spatio-temporal properties of the electric…
Topological defects are ubiquitous from solid state physics to cosmology, where they drive phase transitions by proliferating as domain walls, monopoles or vortices. As quantum excitations, they often display fractional charge and anyonic…
Two-dimensional materials-based field-effect transistors (2DM-FETs) exhibit both ambipolar and unipolar transport types. To physically and compactly cover both cases, we put forward a quasi-Fermi-level phase space (QFLPS) approach to model…
In this work, we experimentally investigate the frequency limit of Hall effect sensor designs based on a 2 dimensional electron gas (2DEG) gallium arsenide/aluminum gallium arsenide (GaAs/AlGaAs) heterostructure. The frequency limit is…
Electronic transport experiments involving the topologically protected states found at the surface of Bi2Se3 and other topological insulators require fine control over carrier density, which is challenging with existing bulk-doped material.…
Here, we report an alternative route to achieve two dimensional electron gas (2DEG) in a semiconductor structure. It has been shown that charge accumulation on the side facets can lead to the formation of 2DEG in a network of c-axis…
When a high electron mobility transistor is illuminated, the absorbed photons excite electron-hole pairs. The generated pairs are separated by the built in field in such a way that the electrons end up in the quantum well generating a…
We suggest an approach for characterizing the zero-field spin splitting of high mobility two-dimensional electron systems, when beats are not readily observable in the Shubnikov-de Haas effect. The zero-field spin splitting and the…
Stacked van der Waals (vdW) heterostructures where semi-conducting two-dimensional (2D) materials are contacted by overlayed graphene electrodes enable atomically-thin, flexible electronics. We use first-principles quantum transport…
We compute the electronic structure of two-dimensional (2D) materials decorated with self-assembled organic monolayers using density functional theory. We find that 2D materials are strongly impacted by near-field electrostatic effects…
We have performed low-temperature transport measurements on a disordered two-dimensional electron system (2DES). Features of the strong localization leading to the quantum Hall effect are observed after the 2DES undergoes a direct…