Co-sputtered MoRe thin films for carbon nanotube growth-compatible superconducting coplanar resonators

Molybdenum rhenium alloy thin films can exhibit superconductivity up to critical temperatures of $T_c=15\mathrm{K}$. At the same time, the films are highly stable in the high-temperature methane / hydrogen atmosphere typically required to grow single wall carbon nanotubes. We characterize molybdenum rhenium alloy films deposited via simultaneous sputtering from two sources, with respect to their composition as function of sputter parameters and their electronic dc as well as GHz properties at low temperature. Specific emphasis is placed on the effect of the carbon nanotube growth conditions on the film. Superconducting coplanar waveguide resonators are defined lithographically; we demonstrate that the resonators remain functional when undergoing nanotube growth conditions, and characterize their properties as function of temperature. This paves the way for ultra-clean nanotube devices grown in situ onto superconducting coplanar waveguide circuit elements.Comment: 8 pages, 6 figure

Non-destructive low-temperature contacts to MoS2\textrm{MoS}_2 nanoribbon and nanotube quantum dots

Molybdenum disulfide nanoribbons and nanotubes are near-one dimensional semiconductors with strong spin-orbit interaction, a nanomaterial highly promising for quantum electronic applications. Here, we demonstrate that a bismuth semimetal layer between the contact metal and this nanomaterial strongly improves the properties of the contacts. Two-point resistances on the order of $100\textrm{k}\Omega$ are observed at room temperature. At cryogenic temperature, Coulomb blockade is visible. The resulting stability diagrams indicate a marked absence of trap states at the contacts and the corresponding disorder, compared to previous devices using low-work function metals as contacts. Single level quantum transport is observed at temperatures below 100mK.Comment: 7 pages, 5 figure

Emergence of anisotropic Gilbert damping in ultrathin Fe layers on GaAs (001)

As a fundamental parameter in magnetism, the phenomenological Gilbert damping constant a determines the performance of many spintronic devices. For most magnetic materials, a is treated as an isotropic parameter entering the Landau-Lifshitz-Gilbert equation. However, could the Gilbert damping be anisotropic? Although several theoretical approaches have suggested that anisotropic a could appear in single-crystalline bulk systems, experimental evidence of its existence is scarce. Here, we report the emergence of anisotropic magnetic damping by exploring a quasi-two-dimensional single-crystalline ferromagnetic metal/semiconductor interface-that is, a Fe/GaAs(001) heterojunction. The observed anisotropic damping shows twofold C-2v symmetry, which is expected from the interplay of interfacial Rashba and Dresselhaus spin-orbit interaction, and is manifested by the anisotropic density of states at the Fe/GaAs (001) interface. This discovery of anisotropic damping will enrich the understanding of magnetization relaxation mechanisms and can provide a route towards the search for anisotropic damping at other ferromagnetic metal/semiconductor interfaces

Detection of large above-ground biomass variability in lowland forest ecosystems by airborne LiDAR

Quantification of tropical forest above-ground biomass (AGB) over large areas as input for Reduced Emissions from Deforestation and forest Degradation (REDD+) projects and climate change models is challenging. This is the first study which attempts to estimate AGB and its variability across large areas of tropical lowland forests in Central Kalimantan (Indonesia) through correlating airborne light detection and ranging (LiDAR) to forest inventory data. Two LiDAR height metrics were analysed, and regression models could be improved through the use of LiDAR point densities as input (<i>R</i>² = 0.88; <i>n</i> = 52). Surveying with a LiDAR point density per square metre of about 4 resulted in the best cost / benefit ratio. We estimated AGB for 600 km of LiDAR tracks and showed that there exists a considerable variability of up to 140% within the same forest type due to varying environmental conditions. Impact from logging operations and the associated AGB losses dating back more than 10 yr could be assessed by LiDAR but not by multispectral satellite imagery. Comparison with a Landsat classification for a 1 million ha study area where AGB values were based on site-specific field inventory data, regional literature estimates, and default values by the Intergovernmental Panel on Climate Change (IPCC) showed an overestimation of 43%, 102%, and 137%, respectively. The results show that AGB overestimation may lead to wrong greenhouse gas (GHG) emission estimates due to deforestation in climate models. For REDD+ projects this leads to inaccurate carbon stock estimates and consequently to significantly wrong REDD+ based compensation payments

Ambulante Pflegedienste. Veraenderungen, wahrnehmen - Ideen umsetzen

SIGLEAvailable from TIB Hannover: U98B101+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany); Ministerium fuer Arbeit, Soziales, Gesundheit und Frauen des Landes Brandenburg, Potsdam (Germany); Kreisverband der Arbeiterwohlfahrt Potsdam e.V. (Germany)DEGerman

H&auml;matologische und immunologische Befunde bei Knochenmarkaplasie.

Zellgehalt des Knochenmarks, Blutzellwerte und Immunglobulinspiegel wurden bei 51 Patienten mit Knochenmarkaplasie bestimmt. Bei dieser Erkrankung ist nicht nur ein Organ der H&auml;matopoese gesch&auml;digt; es lassen sich gleichzeitig St&ouml;rungen des Lymphocyten- sowie des Monocyten-Systems nachweisen: Bei der Mehrzahl der Patienten bestehen Lympho- und Monocytopenie. Bei der Pathogenese der Knochenmarkaplasie scheinen immunologische Reaktionen beteiligt zu sein; so findet sich bei nahezu allen Patienten im Knochenmark eine Plasmazell-, in etwa der H&auml;lfte der F&auml;lle eine Lymphocytenvermehrung. Einzelne oder mehrere Immunglobulinfraktionen sind bei der H&auml;lfte der Kranken vermehrt, bei etwa einem Viertel vermindert

Non‐Destructive Low‐Temperature Contacts to MoS2 Nanoribbon and Nanotube Quantum Dots

Molybdenum disulfide nanoribbons and nanotubes are quasi-one dimensional semiconductors with strong spin-orbit interaction, a nanomaterial highly promising for quantum electronic applications. Here, we demonstrate that a bismuth semimetal layer between the contact metal and this nanomaterial strongly improves the properties of the contacts. Two-point resistances on the order of 100kΩ are observed at room temperature. At cryogenic temperature, Coulomb blockade is visible. The resulting stability diagrams indicate a marked absence of trap states at the contacts and the corresponding disorder, compared to previous devices which use low-work function metals as contacts. Single level quantum transport is observed at temperatures below 100 mK

Tuning Spin Hall Angles by Alloying

Within a combined experimental and theoretical study it is shown that the spin Hall angle of a substitutional alloy system can be continuously varied via its composition. For the alloy system AuxPt1-x a substantial increase of the maximum spin Hall angle compared to the pure alloy partners could be achieved this way. The experimental findings for the longitudinal charge conductivity sigma, the transverse spin Hall conductivity sigma(SH), and the spin Hall angle alpha(SH) could be confirmed by calculations based on Kubo's linear response formalism. Calculations of these response quantities for different temperatures show that the divergent behavior of sigma and sigma(SH) is rapidly suppressed with increasing temperature. As a consequence, sigma(SH) is dominated at higher temperatures by its intrinsic contribution that has only a rather weak temperature dependence

The CRESST dark matter search

The aim of CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) is to search for particle dark matter via elastic scattering off nuclei. The experiment is located at the Laboratori Nazionali del Gran Sasso (LNGS), Italy, and it uses low-background cryogenic detectors with superconducting phase-transition thermometers for the direct detection of WIMPnucleus scattering events. © 2011 Elsevier B.V. All rights reserved