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The shot noise behavior of sequential tunneling through two vertically coupled quantum dots is studied by means of a master equation approach. In particular, we propose a mechanism to observe super-Poissonian shot noise in such a system. The crucial ingredient is the Coulomb interaction between electrons in individual quantum dots.
Resonant tunneling through a single layer of self-assembled quantum dots (QDs) is compared to tunneling through two layers of vertically aligned (stacked) dots. The difference can be viewed as going from a two-dimensional emitter to a zero-dimensional emitter. The temperature dependence of current peaks originating in tunneling through individual QDs and individual stacks is used to clarify this p
We investigate the noise properties of a zero-dimensional InAs quantum dot (QD) embedded in a GaAs-AlAs-GaAs tunneling structure. We observe an approximately linear dependence of the Fano factor and the current as a function of bias voltage. Both effects can be linked to the scanning of the three-dimensional emitter density of states by the QD. At the current step the shape of the Fano factor is m
Closely spaced local gate electrodes are used to electrically define a double quantum dot along an InAs nanowire crystal. By applying a periodic pulse sequence to two plunger gate electrodes controlling the double quantum dot charge configuration, the device is operated as a single electron pump. The authors find that within measurement accuracy, the pumping current equals one electron per cycle f
We report on fabrication of double quantum dots in catalytically grown InAs/InP nanowire heterostructures. In the few-electron regime, starting with both dots empty, our low-temperature transport measurements reveal a clear shell structure for sequential charging of the larger of the two dots with up to 12 electrons. The resonant current through the double dot is found to depend on the orbital cou
We study phonon emission in a GaAs/AlGaAs double quantum dot by monitoring the tunneling of a single electron between the two dots. We prepare the system such that a known amount of energy is emitted in the transition process. The energy is converted into lattice vibrations, and the resulting tunneling rate depends strongly on the phonon scattering and its effective phonon spectral density. We are
We claim that double moments of twoparticle distributions are very sensitive quantities for testing the opposite side quantum number correlations ine + e −-annihilation predicted by the quark parton model. In particular it is found that kaon correlations are extremely transparent in these quantities. This feature survives when the QCD predictedQ 2-dependence is taken into account. We also stress t
This thesis concerns the creation of Majorana bound states (MBSs) -- a type of condensed matter excitations theorized to have exotic and technologically valuable properties. In particular, they could be used to store and manipulate quantum information in a protected way, forming the building blocks of a topological quantum computer. The search for MBSs has been intense since it was realized that t
The growth of III-V nanowires has attracted significant attention due to their superior electrical and optical properties, which are crucial for advanced optoelectronic devices such as lasers and photonic circuits. Since the 1960s, Au has beenextensively used as a catalyst for III-V nanowire growth, with substantial research conducted through both ex situ and in situ techniques. However, Au introd
The constant increase in global energy demand makes it inevitable to find clean means of energy production. Among renewable energy sources, the Sun is the most available source which makes it a versatile solution for energy needs. Tremendous efforts are made to invent and develop new materials for light to energy conversion. The main question is how the newly developed materials react to light and
The cross-disciplinary field of materials science emerged and grew to prominence in the second half of the twentieth century, drawing theoretical and experimental strength from the rapid progress in several natural sciences disciplines and connecting to many industrial applications. In this article, we chronicle and analyze how materials science established itself in Swedish universities in the 19
The effect of initial texture on the stored energy is investigated. Uniaxially loaded polycrystalline materials with initial textures based on the Goss component and the Brass component are analyzed. For reference purposes a single crystal and an initial isotropic crystal orientation distribution are also analyzed. Special attention is directed at the thermomechanical behavior of polycrystalline m
Most of today’s materials show either high strength with low ductility, or relatively low strength combined with high ductility. It is strongly desired in the industry to obtain materials whose mechanical properties can display a combination of high strength and elongation. That is why the new concept of harmonic structure has been introduced recently. This structure consists of strong ultrafine g
This contribution focuses on the sequential laminate-based modelling approach for the numerical simulation of the complex electromechanical material behaviour of ferroelectric single crystals. The construction of engineered domain configurations by using the method of sequential lamination in order to study the domain evolution and polarisation switching in ferroelectric single crystals has recent
The recently introduced Gas in Scattering Media Absorption Spectroscopy (GASMAS) technique is applied to the study of various wood samples. Molecular oxygen in the pores of the strongly scattering material is detected using diode laser spectroscopy around 760 nm. Diffuse light propagation in these media is studied by time-dispersion measurements. Furthermore, anisotropy related to the fibre struct
