Data Science

Obwohl die Schweiz aus der Kernenergie aussteigt, muss sie eine Lösung für das in den Kernkraftwerken, aber auch in Medizin, Industrie und Forschung entstandene, radioaktive Material finden. Daher stellt sie sich einer aussergewöhnlichen, verantwortungsvollen Aufgabe: Sie sucht einen Ort, an dem sie ihre radioaktiven Abfälle mehrere hunderttausend Jahre lang sicher lagern kann. So lange, bis sie von selbst die Radioaktivität natürlicher Gesteine erreicht haben.

A new type of detector developed by Dr. van Genderen enables the structure determination of pharmaceutical compounds with electron diffraction at room temperature. The group concentrate on expanding this new technique to macromolecular compounds.

The transfer rate of a probe molecule across the interfacial layer of a water-in-oil (w/o) microemulsion was investigated using a combination of transverse field muon spin rotation (TF-μSR), avoided level crossing muon spin resonance (ALC-μSR), and Monte Carlo simulations. Reverse micro-emulsions consist of nanometer-sized water droplets dispersed in an apolar solvent separated by a surfactant monolayer.

The determination of the mass density of cellular compartments is one of the many analytical tools that biologists need to unravel the extremely complex structure of biological systems. Cryo X-ray nanotomography reveals absolute mass density maps of frozen hydrated cells in three dimensions.

The discovery of exceptionally well-preserved, tiny fossil seeds dating back to the Early Cretaceous corroborates that flowering plants were small opportunistic colonizers at that time, according to a new Yale-led study.

A new kind of 2DEG is found by inserting two atomic layers of the antiferromagnetic and insulating compound EuTiO₃ between LaAlO₃ and SrTiO₃. The 2DEG is found to exhibit besides a superconducting ground state, a strong spin-polarization. The magnetism of Eu and Ti was studied by XMCD at the X-Treme beamline in SLS.

The macromolecular crystallography beamline X06SA at the Swiss Light Source, a synchrotron operated by Paul Scherrer Institute, is the first one in the world to upgrade its detector to an EIGER X 16M.

In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion.

The mechanical properties of many materials are based on the macroscopic arrangement and orientation of their nanostructure. This nanostructure can be ordered over a range of length scales. In biology, the principle of hierarchical ordering is often used to maximize functionality, such as strength and robustness of the material, while minimizing weight and energy cost.

A specific case of synthetic ultramarine degradation was observed in three oil paintings from the early 20th century. Pigment particleswere found to have been discoloured, resulting in intricate patterns ofwhite lines, approximately 10 to 30 microns wide, criss-crossing the paint surface. Colour in ultramarine pigments comes from the encapsulated sulphur radical anions, chromophores, inside the cage framework built from SiO4 4 − and AlO4 5 −

The study of nontrivial topological semimetals (TSM) is an emerging subject, providing a new frontier in topological aspects beyond insulators. Here, we have investigated the spin texture of surface Fermi arcs in the recently discovered Weyl semimetal TaAs using spin- and angle-resolved photoemission spectroscopy. The experimental results demonstrate that the Fermi arcs are spin polarized. The measured spin texture fulfills the requirement of mirror and time-reversal symmetries and is well reproduced by our first-principles calculations, which gives strong evidence for the topologically nontrivial Weyl semimetal state in TaAs. The consistency between the experimental and calculated results further confirms the distribution of chirality of the Weyl nodes determined by first principles calculations.

At the PEARL beamline, metal-supported ultrathin oxide films have been studied which are a class of materials of technological importance in various research fields such as catalysis, spintronics, or nanoelectronics.

Polymer solar cells are in the spotlight for sustainable energy production of the future. Characterization of these devices by X-ray nanotomography helps to improve their production using environmentally friendly materials.

We report microscopic studies by muon spin rotation/relaxation as a function of pressure of the Ca₃Ir₄Sn₁₃ and Sr₃Ir₄Sn₁₃ cubic compounds, which are members of the (Ca_1−xSr_x)₃Ir₄Sn₁₃ system displaying superconductivity and a structural phase transition associated with the formation of a charge density wave (CDW).

At the imaging Photoelectron Photoion Coincidence (iPEPICO) endstation of the VUV beamline evidence of H-atom tunneling was shown.

The superconducting gap structure in iron-based high-temperature superconductors (Fe-HTSs) is non-universal. In contrast to other unconventional superconductors, in the Fe-HTSs both d-wave and extended s-wave pairing symmetries are close in energy. Probing the proximity between these very different superconducting states and identifying experi- mental parameters that can tune them is of central interest.

In 1933, Meissner and Ochsenfeld reported the expulsion of magnetic flux - the diamagnetic Meissner effect - from the interior of superconducting lead. This discovery was crucial in formulating the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity. In exotic superconducting systems BCS theory does not strictly apply.

EUCALL will build bridges between major laser and X-ray research centres: For the past half-century, two special kinds of light have changed the landscape of research. Advanced visible-spectrum optical lasers have propelled studies into ultrafast processes, new materials, telecommunications, and many other fields, while intense X-rays produced at synchrotrons have helped image tiny structures and otherwise invisible parts of matter, enabling huge leaps in biochemistry, pharmacology, and materials science. New developments have enhanced the generation of X-rays at optical-laser and accelerator facilities, resulting in the creation of large international research centres. The European Union is now funding a 7 million-euro effort to bring these research centres together through the European Cluster of Advanced Laser Light Sources (EUCALL) project.

Alike materials in the solid state, the phase diagram of type-II superconductors exhibit crystalline, amorphous, liquid and spatially inhomogeneous phases. The multitude of different phases of vortex matter has thence proven to act as almost ideal model system for the study of both the underlying properties of superconductivity but also of general phenomena such as domain nucleation and morphology.

Alike materials in the solid state, the phase diagram of type-II superconductors exhibit crystalline, amorphous, liquid and spatially inhomogeneous phases. The multitude of different phases of vortex matter has thence proven to act as almost ideal model system for the study of both the underlying properties of superconductivity but also of general phenomena such as domain nucleation and morphology.

Researchers from the Paul Scherrer Institute PSI have succeeded in using commercially available camera technology to visualise terahertz light. In doing so, they are enabling a low-cost alternative to the procedure available to date, whilst simultaneously increasing the comparative image resolution by a factor of 25. The special properties of terahertz light make it potentially advantageous for many applications, from safety technology to medical diagnostics.