Related papers: Antilocalization in gated 2D quantum well structur…
In a high mobility two-dimensional electron gas (2DEG) in a GaAs/AlGaAs quantum well we observe a strong magnetoresistance. In lowering the electron density the magnetoresistance gets more pronounced and reaches values of more than 300%. We…
Thanks to their multi-valley, anisotropic, energy band structure, two-dimensional electron systems (2DESs) in modulation-doped AlAs quantum wells (QWs) provide a unique platform to investigate electron interaction physics and ballistic…
Here we investigate the spin-dependent subband structure of newly-developed Mn-based modulation-doped quantum wells. In the presence of an external magnetic field, the s-d exchange coupling between carriers and localized d electrons of the…
The relative strengths of Rashba and Dresselhaus terms describing the spin-orbit coupling in semiconductor quantum well (QW) structures are extracted from photocurrent measurements on n-type InAs QWs containing a two-dimensional electron…
We calculate using the Boltzmann transport theory the density dependent mobility of two-dimensional (2D) electrons in GaAs, SiGe and AlAs quantum wells as well as of 2D holes in GaAs quantum wells. The goal is to precisely understand the…
Metrological investigations of the quantum Hall effect (QHE) completed by transport measurements at low magnetic field are carried out in a-few-$\mu\mathrm{m}$-wide Hall bars made of monolayer (ML) or bilayer (BL) exfoliated graphene…
Superfluidity in the quasi-two-dimensional (2D) system of spatially indirect magnetoexcitons in coupled quantum wells (CQW) and unbalanced two-layer electron system in high magnetic field $H$ is considered in the presence of a random field.…
Nonlocality is a key feature discriminating quantum and classical physics. Quantum-interference phenomena, such as Young's double slit experiment, are one of the clearest manifestations of nonlocality, recently addressed as $dynamical$ to…
We employ magnetocapacitance and far-infrared spectroscopy techniques to study the spectrum of the double-layer electron system in a parabolic quantum well with a narrow tunnel barrier in the centre. For gate-bias-controlled asymmetric…
In double quantum wells electrons experience a Lorentz force oriented perpendicular to the structure plane when an electric current is driven perpendicular to the direction of an in-plane magnetic field. Consequently, the excess charge is…
A theory of transport in the quantum Hall regime is developed for separately contacted double-layer electron systems. Inter-layer tunneling provides a channel for equilibration of the distribution functions in the two layers and influences…
We report on the observation of magnetic quantum ratchet effect in (Cd,Mn)Te- and CdTe-based quantum well structures with an asymmetric lateral dual grating gate superlattice subjected to an external magnetic field applied normal to the…
The polarizability of electrons occupying the lowest subband of spatial quantization in CdTe/Cd$_x$Hg$_{1-x}$Te/CdTe quantum wells is calculated. It is shown that polarizability in the quantum well without cadmium is negative, i.e., the…
In this study, we present our experimental investigation on the magnetotransport properties of a two-dimensional electron system in GaAs quantum wells utilizing a variety of device geometries, including obstacles with thin barriers and…
Recently, Dial et al. presented measurements of the tunneling density of states into the bulk of a two dimensional electron gas under strong magnetic fields. Several high energy features appear in the measured spectrum showing a distinct…
The aim of this thesis is to investigate quantum entanglement and quantum nonlocality of bipartite finite-dimensional systems (bipartite qudits). Entanglement is one of the most fascinating non-classical features of quantum theory, and…
Metal-oxide-semiconductor field-effect transistors (MOSFET's) using atomic-layer-deposited (ALD) Al$_2$O$_3$ as the gate dielectric are fabricated on the Si/Si$_{1-x}$Ge$_x$ heterostructures. The low-temperature carrier density of a…
Slow magnetooscilations of the conductivity are observed in a 75 nm wide quantum well at heating of the two-dimensional electrons by a high-intensity surface acoustic wave. These magnetooscillations are caused by intersubband elastic…
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…
Collective properties of a quasi-two-dimensional (2D) system of spatially indirect magnetoexcitons in coupled quantum wells (CQW) in high magnetic field $H$ were analyzed in the presence of disorder. The Hamiltonian of the dilute gas of…