Forschung zu Covid-19

Artificial spin ices consist of nanomagnets arranged on the sites of various periodic and aperiodic lattices. They have enabled the experimental investigation of a variety of fascinating phenomena such as frustration, emergent magnetic monopoles and phase transitions that have previously been the domain of bulk spin crystals and theory, as we discuss in this Review.

Strongly correlated kagome magnets are promising candidates for achieving controllable topological devices owing to the rich interplay between inherent Dirac fermions and correlation-driven magnetism. Here we report tunable local magnetism and its intriguing control of topological electronic response near room temperature in the kagome magnet Fe₃Sn₂ using small angle neutron scattering, muon spin rotation, and magnetoresistivity measurement techniques.

Shape-morphing systems, which can perform complex tasks through morphological transformations, are of great interest for future applications in minimally invasive medicine, soft robotics, active metamaterials and smart surfaces. With current fabrication methods, shape-morphing configurations have been embedded into structural design by, for example, spatial distribution of heterogeneous materials, which cannot be altered once fabricated. 

FRS researchers present a classification model for sorting energy accidents in the natural gas sector into hazard classes, according to their potential fatalities.

In addition to the Kitaev (K) interaction, candidate Kitaev materials also possess Heisenberg (J) and off- diagonal symmetric (Γ) couplings. We investigate the quantum (S=1/2) K-J-Γ model on the honeycomb lattice by a variational Monte Carlo method. In addition to the “generic” Kitaev spin liquid (KSL), we find that there is just one proximate KSL (PKSL) phase, while the rest of the phase diagram contains different magnetically ordered states.

The Energy Economics Group quantified the new World Energy Scenarios 2019 in collaboration with the World Energy Council and Accenture Strategy. The three scenarios (named "Modern Jazz", "Unfinished Symphony", and "Hard Rock") depict possible future developments of the global energy systems until 2040 and were presented at the World Energy Congress 2019 in Dubai.

Researchers in a joint collaboration between the PolLux endstation of the Swiss Light Source and the University of Leeds have achieved the reliable and reproducible electrical nucleation of magnetic skyrmions from a nano-engineered point contact structure, investigating the physical mechanisms driving the nucleation process.

Interrupted standard tensile tests with in situ x-ray diffraction and quasi-in situ electron backscatter diffraction reveal the origin behind the work hardening plateau and springback.

Between the years 2015 and 2019, PSI coordinated a project investigating the pebble bed high temperature gas-cooled (HTGR) reactor aside with molten salt reactor (MSR) concepts and the use of thorium fuel. The project involved different groups from the ETH domain and the main purpose is to build-up the specific know-how in Switzerland that is necessary to provide in-depth information to decision makers and identify research needs for the future. Several key aspects of both HTGR and MSR reactors were addressed in this research project. These include economic and accident phenomenology studies of the HTGR, fuel cycle optimization of both MSR and HTGR, as well as a study on waste volume reduction of the pebble bed reactors.

Researchers of the Paul Scherrer Institut have previously generated 3-D images of a commercially available computer chip. This was achieved using a high-resolution tomography method. Now they extended their imaging approach to a so-called laminography geometry to remove the requirement of preparing isolated samples, also enabling imaging at various magnification. For ptychographic X-ray laminography (PyXL) a new instrument was developed and built, and new data reconstruction algorithms were implemented to align the projections and reconstruct a 3D dataset. The new capabilities were demonstrated by imaging a 16 nm FinFET integrated circuit at 18.9 nm 3D resolution at the Swiss Light Source. The results are reported in the latest edition of the journal Nature Electronics. The imaging technique is not limited to integrated circuits, but can be used for high-resolution 3D imaging of flat extended samples. Thus the researchers start now to exploit other areas of science ranging from biology to magnetism.

A research team centered at the X-Treme beam line at the Swiss Light Source has demonstrated that spin-phonon coupling plays a major role in enhancing the magnetic stability of so-called lanthanide phthalocyanine double decker single-molecule magnets. This understanding is important in order to employ such molecules in future spintronics applications.

The IEEE Nuclear Plasma Science Society has recently awarded Dr. Paolo Craievich, leader of the group «RF-system 2» in GFA, with the Particle Accelerator Science Technology award for his exceptional contributions to accelerator science and technology. https://www.frib.msu.edu/events/2019/napac19/awards.html

We report muon spin rotation and magnetization measurements under pressure on Fe_1+δSe_1−xS_x with x ≈ 0.11. Above p ≈ 0.6 GPa we find a microscopic coexistence of superconductivity with an extended dome of long range magnetic order that spans a pressure range between previously reported separated magnetic phases. 

Via femtosecond x-ray diffraction, we observe an ultrafast increase of the octahedral rotation angle in the perovskite EuTiO₃ after ultrafast laser excitation. This is opposite to what is expected from an increase in temperature. We ascribe this increase to an effective change of ionic sizes that transforms directly into a change of the Goldschmidt tolerance factor. Rotating oxygen octahedra at will opens up the possibility to control electronic and magnetic properties of perovskites on ultrafast timescales.