Related papers: Complex optical signatures from quantum dot nanost…
The emission cascade of a single quantum dot is a promising source of entangled photons. A prerequisite for this source is the use of a symmetric dot analogous to an atom in a vacuum, but the simultaneous achievement of structural symmetry…
By combining band gap engineering with the self-organized growth of quantum dots, we present a scheme of adjusting the mid-infrared absorption properties to desired energy transitions in quantum dot based photodetectors. Embedding the self…
This study compares cross-sectional scanning tunnelling microscopy (XSTM) and atom probe tomography (APT). We use epitaxially grown self-assembled InAs quantum dots (QDs) in GaAs as an exemplary material with which to compare these two…
We present here the electronic structure and optical properties of InGaAs quantum wells with barrier doped with Manganese. We calculated the electronic states and optical emission within the envelope function and effective mass…
We report the fabrication and photoluminescence properties of laterally-coupled GaAs/AlGaAs quantum dots. The coupling in the quantum dot molecules is tuned by an external electric field. An intricate behavior, consisting of spectral line…
Self-assembled quantum dots based on III-V semiconductors have excellent properties for applications in quantum optics. However, the presence of a 2D wetting layer which forms during the Stranski-Krastanov growth of quantum dots can limit…
We report the realization of a hybrid superconductor-quantum dot device by means of top-down nanofabrication starting from a two dimensional electron gas in a InGaAs/InAlAs semiconductor heterostructure. The quantum dot is defined by…
We have investigated the band-gap pressure coefficients of self-assembled InAs/GaAs quantum dots by calculating 17 systems with different quantum dot shape, size, and alloying profile using atomistic empirical pseudopotential method within…
Understanding the carrier dynamics of nanostructures is the key for development and optimization of novel semiconductor nano-devices. Here, we study the optical properties and carrier dynamics of (InGa)(AsSb)/GaAs/GaP quantum dots (QDs) by…
Combining the capabilities of gate defined quantum transport devices in GaAs-based heterostructures and of optically addressed self-assembled quantum dots could open broad perspectives for new devices and functionalities. For example,…
A systematic variation of the exciton fine-structure splitting with quantum dot size in single InAs/GaAs quantum dots grown by metal-organic chemical vapor deposition is observed. The splitting increases from -80 to as much as 520 $\mu$eV…
It has been recently shown that a nanostructure composed of a quantum dot surrounded by a quantum ring possesses a set of very unique characteristics that make it a good candidate for future nanoelectronic devices. Its main advantage is the…
We study experimentally the dependence of dynamic nuclear spin polarization on the power of non-resonant optical excitation in two types of individual neutral semiconductor quantum dots: InGaAs/GaAs and GaAs/AlGaAs. We show that the…
In a model of a gate-patterned quantum device it is important to choose the correct electrostatic boundary conditions (BCs) in order to match experiment. In this study, we model gated-patterned devices in doped and undoped GaAs…
The design of some optical devices such as semiconductor optical amplifiers for telecommunication applications requires polarization-insensitive optical emission at the long wavelengths (1300-1550 nm). Self-assembled InAs/GaAs quantum dots…
A method for the calculation of the electronic structure of pyramidal self-assembled InAs/GaAs quantum dots is presented. The method is based on exploiting the exact $\bar{C}_{4}$ symmetry of the 8-band $k\cdot p$ Hamiltonian with the…
In this paper we present a detailed analysis of the atomic and electronic structure of GaAs nanowires using first-principles pseudopotential calculations. We consider six different types of nanowires with different diameters all grown along…
Heteroepitaxy on nanopatterned substrates is a means of defect reduction at semiconductor heterointerfaces by exploiting substrate compliance and enhanced elastic lattice relaxation resulting from reduced dimensions. We explore this…
The slowdown of optical pulses due to quantum-coherence effects is investigated theoretically for an "active material" consisting of InGaAs-based double quantum-dot molecules. These are designed to exhibit a long lived coherence between two…
Shallow GaAs/InGaAs/GaAs quantum well structures with and without a three monolayer thick AlAs central barrier have been investigated for different well widths and Si doping levels. The transport parameters are determined by resistivity…