A5025847433- Avian ecology and behavior
- Animal Behavior and Reproduction
- European Monetary and Fiscal Policies
- Scientific Measurement and Uncertainty Evaluation
- European Union Policy and Governance
- Law and Political Science
- Radioactive Decay and Measurement Techniques
- Bird parasitology and diseases
- Wildlife Ecology and Conservation
- European history and politics
- Economic and Social Issues
- Quantum and electron transport phenomena
- Medical and Health Sciences Research
- Mercury impact and mitigation studies
- European and International Law Studies
- Public Administration and Political Analysis
- Plant and animal studies
- Silicon and Solar Cell Technologies
- Social Policy and Reform Studies
- Toxic Organic Pollutants Impact
- Nuclear Physics and Applications
- German Literature and Culture Studies
- Semiconductor materials and interfaces
- X-ray Diffraction in Crystallography
- Crystallography and Radiation Phenomena
Stiftung Wissenschaft und Politik, German Institute for International and Security Affairs
2011-2025
Ulrich Medical (Germany)
2024
Ludwigsburg University of Education
2024
Stuttgart Observatory
2024
University of Göttingen
2024
Justus-Liebig-Universität Gießen
2024
Humboldt-Universität zu Berlin
2024
University of Vienna
2020-2023
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2014-2023
Leibniz-Centre for Contemporary History
2023
Quantum memories capable of storing and retrieving coherent information for extended times at room temperature would enable a host new technologies. Electron nuclear spin qubits using shallow neutral donors in semiconductors have been studied extensively but are limited to low temperatures ($\le$10 K); however, the spins ionized potential high operation. We use optical methods dynamical decoupling realize this an ensemble 31P isotopically purified 28Si observe coherence time over 39 minutes....
Abstract Comparative analyses of survival senescence by using life tables have identified generalizations including the observation that mammals senesce faster than similar‐sized birds. These been challenged because limitations life‐table approaches and growing appreciation is more an increasing probability death. Without tables, we examine rates in annual individual fitness 20 individual‐based data sets terrestrial vertebrates with contrasting histories body size. We find widespread wild...
Extending Quantum Memory Practical applications in quantum communication and computation require the building blocks—quantum bits memory—to be sufficiently robust long-lived to allow for manipulation storage (see Perspective by Boehme McCarney ). Steger et al. (p. 1280 ) demonstrate that nuclear spins of 31 P impurities an almost isotopically pure sample 28 Si can have a coherence time as long 192 seconds at temperature ∼1.7 K. In diamond room temperature, Maurer 1283 show spin-based qubit...
The quantum superposition principle states that an entity can exist in two different simultaneously, counter to our 'classical' intuition. Is it possible understand a given system's behaviour without such concept? A test designed by Leggett and Garg rule out this possibility. test, originally intended for macroscopic objects, has been implemented various systems. However date no experiment employed the 'ideal negative result' measurements are required most robust test. Here we introduce...
The general characteristics and spectrometric features of a high resolution four-crystal reflection x-ray monochromator with wavelength analysis installed at the HASYLAB beam line L DESY are presented. is part spectrometer developed to calibrate absorption edge spectra in energy range 6–36 keV relative uncertainty ΔE/E from 10−5 10−6. This requires an extremely effective suppression harmonics also negligible instrumental influence order obtain almost intrinsic spectra. As results show,...
The (220) lattice plane spacing of an almost perfect crystal silicon was measured by means a combined scanning ($\mathrm{LLL}$) x-ray interferometer and two-beam optical interferometer. From 170 measurements, value ${d}_{220}=(192015.560\ifmmode\pm\else\textpm\fi{}0.012)$ fm results in vacuum at 22.50\ifmmode^\circ\else\textdegree\fi{}C. This is smaller $1.8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}{d}_{220}$ than that reported Deslattes et al. for another crystal. Generic...
The Avogadro constant links the atomic and macroscopic properties of matter. Since molar Planck is well known via measurement Rydberg constant, it also closely related to constant. In addition, its accurate determination paramount importance for a definition kilogram in terms fundamental We describe new approach by counting atoms 1 kg single-crystal spheres, which are highly enriched with 28Si isotope. It enabled isotope dilution mass spectroscopy determine silicon crystal unprecedented...
A major question in ecology is how age-specific variation demographic parameters influences population dynamics. Based on long-term studies of growing populations birds and mammals, we analyze dynamics by using fluctuations the total reproductive value population. This enables us to account for random age distribution. The influence environmental stochasticity a species decreased with generation time. Variation contributions stochastic components was correlated position along slow-fast...
This paper concerns an international research project aimed at determining the Avogadro constant by counting atoms in isotopically enriched silicon crystal. The procedure was based on measurement of molar volume and atom two 1 kg crystal spheres. novelty use isotope dilution mass spectrometry as a new very accurate method for determination silicon. Because unexpected metallic contamination sphere surfaces, relative uncertainty, 3 × 10−8 NA, is larger factor 1.5 than that targeted. measured...
Telomere length is associated with cellular senescence, lifestyle and ageing. Short telomeres indicate poor health in humans reduced life expectancy several bird species, but little known about relation to phenotypic quality wild animals. We investigated telomere lengths erythrocytes of known-age common terns (Sterna hirundo), a migratory seabird, arrival date reproductive performance. Cross-sectional data revealed that, independent age, individuals short performed better: they arrived...
The advantages of the step-scan mode over a continuous scan in X-ray data collection are discussed. Computer analysis recorded profile allows corrections for effects such as non-uniform background, β-filter cut-off, thermal diffuse scattering, and counter dead time, well reduction experimental standard deviations. It is concluded that should be avoided careful crystallographic studies.
Heterogeneity within a population is pervasive challenge for studies of individual life-histories. Population-level patterns in age-specific reproductive success can be broken down into relative contributions from selective disappearance, appearance individuals the study population, and average change performance survivors (average ontogenetic development). In this article, we provide an exact decomposition. We apply our formula to data on well characterized common terns (Sterna hirundo)....
When the kilogram is redefined in terms of fixed numerical value Planck constant h, x-ray-crystal-density (XRCD) method, among others, used for realizing kilogram. The XRCD method has been determination Avogadro NA by counting number atoms a 28Si-enriched crystal, contributing to substantial reduction uncertainty values and h 2 parts 108. This can be therefore reversely mass 1 kg sphere prepared from crystal. realized SI-traceable measurements its lattice parameter, isotopic composition,...
A new single crystal from isotopically enriched silicon was used to determine the Avogadro constant NA by x-ray-crystal density method. The crystal, named Si28-23Pr11, has a higher enrichment than former 'AVO28' allowing smaller uncertainty of molar mass determination. Again, two 1 kg spheres were manufactured this crystal. and measured with improved methods. One sphere, Si28kg01a, at NMIJ PTB very consistent results. other Si28kg01b, only yielded nearly same value. mean result for both is =...
The conditions under which individuals are reared vary and sensitivity of offspring to such variation is often sex-dependent. Parental age one important natal condition with consequences for aspects fitness, but reports mostly limited short-term fitness do not take into account sex. Here we used individual-based data from a large colony long-lived seabird, the common tern Sterna hirundo, investigate longitudinal long-term parental in relation both We found that recruited daughters older...
Long-distance entanglement distribution is a vital capability for quantum technologies. An outstanding practical milestone towards this aim the identification of suitable matter-photon interface which possesses, simultaneously, long coherence lifetimes and efficient telecommunications-band optical access. In work, alongside its sister publication, we report upon T center, silicon defect with spin-selective transitions at 1326 nm in telecommunications O-band. Here show that center $^{28}$Si...
Donor spins in silicon are highly competitive qubits for upcoming quantum technologies, offering complementary metal-oxide semiconductor compatibility, coherence (T2) times of minutes to hours, and simultaneous initialization, manipulation, readout fidelities near ~99.9%. This allows many error correction protocols, which will be essential scale-up. However, a proven method reliably coupling spatially separated donor has yet identified. We present scalable silicon-based platform using the...