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Template-Assisted Scalable Nanowire Networks

Topological qubits based on Majorana Fermions have the potential to revolutionize the emerging field of quantum computing by making information processing significantly more robust to decoherence. Nanowires are a promising medium for hosting these kinds of qubits, though branched nanowires are needed to perform qubit manipulations. Here we report a gold-free templated growth of III-V nanowires by

Anisotropic-Strain-Induced Band Gap Engineering in Nanowire-Based Quantum Dots

Tuning light emission in bulk and quantum structures by strain constitutes a complementary method to engineer functional properties of semiconductors. Here, we demonstrate the tuning of light emission of GaAs nanowires and their quantum dots up to 115 meV by applying strain through an oxide envelope. We prove that the strain is highly anisotropic and clearly results in a component along the NW lon

Bistability of Contact Angle and Its Role in Achieving Quantum-Thin Self-Assisted GaAs nanowires

Achieving quantum confinement by bottom-up growth of nanowires has so far been limited to the ability of obtaining stable metal droplets of radii around 10 nm or less. This is within reach for gold-assisted growth. Because of the necessity to maintain the group III droplets during growth, direct synthesis of quantum sized structures becomes much more challenging for self-assisted III-V nanowires.

Engineering the Size Distributions of Ordered GaAs Nanowires on Silicon

Reproducible integration of III-V semiconductors on silicon can open new path toward CMOS compatible optoelectronics and novel design schemes in next generation solar cells. Ordered arrays of nanowires could accomplish this task, provided they are obtained in high yield and uniformity. In this work, we provide understanding on the physical factors affecting size uniformity in ordered GaAs arrays g

Molecular beam epitaxy of InAs nanowires in SiO2 nanotube templates : challenges and prospects for integration of III-Vs on Si

Guided growth of semiconductor nanowires in nanotube templates has been considered as a potential platform for reproducible integration of III-Vs on silicon or other mismatched substrates. Herein, we report on the challenges and prospects of molecular beam epitaxy of InAs nanowires in SiO2/Si nanotube templates. We show how and under which conditions the nanowire growth is initiated by In-assisted

Synthesis, Morphological, and Electro-optical Characterizations of Metal/Semiconductor Nanowire Heterostructures

In this letter, we demonstrate the formation of unique Ga/GaAs/Si nanowire heterostructures, which were successfully implemented in nanoscale light-emitting devices with visible room temperature electroluminescence. Based on our recent approach for the integration of InAs/Si heterostructures into Si nanowires by ion implantation and flash lamp annealing, we developed a routine that has proven to b

Nonstoichiometric Low-Temperature Grown GaAs Nanowires

The structural and electronic properties of nonstoichiometric low-temperature grown GaAs nanowire shells have been investigated with scanning tunneling microscopy and spectroscopy, pump-probe reflectivity, and cathodoluminescence measurements. The growth of nonstoichiometric GaAs shells is achieved through the formation of As antisite defects, and to a lower extent, after annealing, As precipitate

High Yield of GaAs Nanowire Arrays on Si Mediated by the Pinning and Contact Angle of Ga

GaAs nanowire arrays on silicon offer great perspectives in the optoelectronics and solar cell industry. To fulfill this potential, gold-free growth in predetermined positions should be achieved. Ga-assisted growth of GaAs nanowires in the form of array has been shown to be challenging and difficult to reproduce. In this work, we provide some of the key elements for obtaining a high yield of GaAs

Microscopic coexistence of superconductivity and magnetism in Ba(1-x)K(x)Fe2As2

It is widely believed that, in contrast to its electron-doped counterparts, the hole-doped compound Ba(1-x)K(x)Fe(2)As(2) exhibits a mesoscopic phase separation of magnetism and superconductivity in the underdoped region of the phase diagram. Here, we report a combined high-resolution x-ray powder diffraction and volume-sensitive muon spin rotation study of Ba(1-x)K(x)Fe(2)As(2) showing that this

A novel approach for applied membrane filtration on processing flows

Membrane filtration technique shows exclusively properties for optimized filtration for a given size, from micrometer to nanometer scales compared to other industrial filtration. However, there is a trade off in flux that has delayed the implementation of the membrane techniques for a wider range of applications. For a specific flow in a process stream, the limited flux through the membrane means

Osynliga pengar : Kulturella perspektiv på ett kontantlöst samhälle

I texten diskuteras vilka kulturella och sociala konsekvenser en snabb tillbakagång för kontanter till fördel för andra betalningssätt kan komma att få. Vem riskerar att lämnas utanför en snabb digital utveckling och hur förändras pengars kulturella och symboliska mening?

Performance of the EUDET-type beam telescopes

Test beam measurements at the test beam facilities of DESY have been conducted to characterise the performance of the EUDET-type beam telescopes originally developed within the EUDET project. The beam telescopes are equipped with six sensor planes using MIMOSA 26 monolithic active pixel devices. A programmable Trigger Logic Unit provides trigger logic and time stamp information on particle passage

Industrial applications of ultrafiltration in the pharmaceutical biotechnology

In pharmaceutical biotechnology, ultrafiltration with diafiltration for recovery of fermentation products on an industrial scale is now the state-of-the-art technology. To optimise this process, DSS has developed two new concepts: (1) an optimised control system for constant permeate concentration even at varying feed streams and (2) continuous counter-current diafiltration to significantly reduce

Applications and challenges of membrane processes in wine production

The membrane market for the food and beverage industry of which the wine market has a significant share developed to the second largest market after municipal water treatment in Europe. The trend in the wine market towards larger volumes combined with an improved quality leads to a constant investment for upgrading and updating present product facilities. There are several interesting positions of

An Early Ordovician 40Ar-39Ar age for the ∼50 km Carswell impact structure, Canada

The formation age of the large (∼50 km) Carswell impact structure, Canada, has been a matter of debate ever since its discovery five decades ago, with proposed ages ranging from Mesoproterozoic to Early Cretaceous. Here, we present new 40Ar-39Ar data for aliquots of euhedral adularia, separated from vesicles in an impact melt rock from the central uplift of the structure. The analyses of the adula

Optimisation and integration of membrane processes in the beverage industry

Potential applications of membrane technology for the beverage industry will be presented by two case studies. The focus of the first case study is on the clarification and concentration of fruit juice. A novel combination of a centrifuge with ultrafiltration for the clarification will be discussed together with the combination of an evaporator combined with reverse osmosis for the concentration.

Excellent survival and low complication rate in medium-term follow-up after arterial switch operation for complete transposition

Objective—To determine medium-term outcome after arterial switch operation for complete transposition in a population-based cohort.Design—Retrospective study of all 86 patients operated on at our institution from 1982 to 2000. Age at operation was 0-256 days (median 6 days); 28 (32%) had closure of a ventricular septal defect, 2 of whom had double outlet right ventricle. Additional surgery include