Scientific Highlights LSM
Benefit of random testing
With the imminent relaxation of socio-economic restrictions, it becomes vital to assess its effect on the prevalence of acute infections within the population, as rapidly as possible. Currently available monitoring instruments for the COVID-19 pandemic have an inherent time delay of about 14 days, as they rely on confirmed infections, hospitalizations, and death numbers. These methods give Reff(t) (the number of infections caused by a single infected person), but their delay is a significant disadvantage when restrictions are released. If after relaxation, Reff(t) rises above 1, one will not be able to react adequately before two weeks have passed during which time the prevalence could significantly rise. Here, we propose the use of random testing to shorten this reaction time, by obtaining direct and modeling dependent information on Reff(t). Through random testing of between 2500 and 20000 people per day, we find that over periods significantly shorter than two weeks, it becomes possible to detect a dangerous increase in Reff with reasonable confidence.
Simulation: The third pillar of science
PSI researchers simulate and model large-scale research facilities as well as experiments, for example, in the materials and biological sciences. Andreas Adelmann, head of PSI's Laboratory for Scientific Computing and Modelling, explains how they do it.
Modelling and simulation pay off
Researchers in PSI's Laboratory for Scientific Computing and Modelling solve the most complex problems through a combination of theory, modelling, and high-performance computing. With powerful computers, they simulate the smallest molecules or large-scale research facilities.
Spin fluctuation induced Weyl semimetal state in the paramagnetic phase of EuCd2As2
Weyl fermions as emergent quasiparticles can arise in Weyl semimetals (WSMs) in which the energy bands are nondegenerate, resulting from inversion or time-reversal symmetry breaking. Nevertheless, experimental evidence for magnetically induced WSMs is scarce. Here, using photoemission spectroscopy, we observe that the degeneracy of Bloch bands is already lifted in the paramagnetic phase of EuCd2As2. We attribute this effect to the itinerant electrons experiencing quasi-static and quasi–long-range ferromagnetic fluctuations.
New material with magnetic shape memory
PSI researchers have developed a material whose shape memory is activated through magnetism. Application areas for this new kind of composite material include, for example, medicine, space flight, electronics, and robotics.
Horizon 2020 project SAMOSAFER granted
The EU Horizon 2020 program granted 3.5 million Euros to the research and innovation project SAMOSAFER, where PSI is one of the 14 project partners. The total budget of the project, inclusive own and in-kind contributions, is 4.5 million Euros. The aim of SAMOSAFER project is to develop and demonstrate new safety barriers and a more controlled behaviour in severe accidents of the Molten Salt Reactor (MSR). Three groups at PSI will be involved in the project: the LSM groups for Advanced Nuclear Systems (ANS) and Multiscale Materials Modelling (MMM) and the Severe Accidents Research group (Sacre) of LRT, focusing on redistribution of the source term in the fuel treatment unit of MSR and assessment and reduction of radionuclide mobility during accidental conditions.
Time-Reversal Symmetry Breaking in Re-Based Superconductors
To trace the origin of time-reversal symmetry breaking (TRSB) in Re-based superconductors, we performed comparative muon-spin rotation and relaxation (μSR) studies of superconducting noncentro-symmetric Re0.82Nb0.18 (Tc=8.8 K) and centrosymmetric Re (Tc=2.7 K).
EPFL Adjunct Professorship to Christopher Mudry
Dr Christopher Mudry, who joined PSI in 1999 and is Research Group Leader of the Condensed Matter Theory Group at PSI since 2009, was awarded the title of Adjunct Professor at EPF Lausanne with the following citation. "Dr Christopher Mudry is a highly acclaimed theoretical physicist. He is regarded as one of the world’s leading experts on the quantum field theory of condensed matter and in the rapidly developing field of the topological properties of matter."
Progress in non intrusive laser based measurements of gas-phase thermoscalars and supporting modeling near catalytically reacting interfaces
Heterogeneous and combined hetero/homogeneous chemical processes have attracted increased attention in many energy conversion systems, which include large scale power generation, microreactors for portable power generation, household burners, fuel processing technologies and automotive exhaust gas aftertreatment. Progress in such systems crucially depends on the development of catalysts with enhanced activity and thermal stability and on the comprehensive understanding of the fundamental processes occurring near gas solid reacting interfaces.