Scientific Highlights from PSI's research divisions
Research with Neutrons and Muons (NUM)
Colossal magnetoresistance in a nonsymmorphic antiferromagnetic insulator
Here we investigate antiferromagnetic Eu5In2Sb6, a nonsymmorphic Zintl phase. Our electrical transport data show that Eu5In2Sb6 is remarkably insulating and exhibits an exceptionally large negative magnetoresistance, which is consistent with the presence of magnetic polarons. From ab initio calculations, the paramagnetic state of Eu5In2Sb6 is a topologically nontrivial semimetal within the generalized gradient approximation (GGA), whereas an insulating state with trivial topological indices is obtained using a modified Becke−Johnson potential.
Handedness-dependent quasiparticle interference in the two enantiomers of the topological chiral semimetal PdGa
It has recently been proposed that combining chirality with topological band theory results in a totally new class of fermions. Understanding how these unconventional quasiparticles propagate and interact remains largely unexplored so far. Here, we use scanning tunneling microscopy to visualize the electronic properties of the prototypical chiral topological semimetal PdGa.
Photon Science Division (PSD)
The tiniest secrets of integrated circuits revealed
New research has demonstrated that the secrets of the tiniest active structures in integrated circuits can be revealed using a non-destructive imaging technique. The breakthrough required the efforts of an international team of scientists from JKU and Keysight Technologies (Austria), ETH/EPFL/PSI and IBM Research - Europe (Switzerland) and from UCL (UK).
Cherned up to the maximum
In topological materials, electrons can display behaviour that is fundamentally different from that in ‘conventional’ matter, and the magnitude of many such ‘exotic’ phenomena is directly proportional to an entity known as the Chern number. New experiments establish for the first time that the theoretically predicted maximum Chern number can be reached — and controlled — in a real material.
Biology and Chemistry (BIO)
Informationen in die Zelle bringen
Forschende des Paul Scherrer Instituts PSI haben einen wichtigen Teil eines Signalweges aufgeklärt, der Informationen durch die Zellmembran in das Innere einer Zelle überträgt. Dieser existiert bei allen Säugetieren und spielt unter anderem bei der Regulierung des Herzschlages eine wichtige Rolle. Die neuen Erkenntnisse könnten zu neuen Therapien führen.
Eine biotechnologische Revolution
Gebhard Schertler ist Leiter des Forschungsbereichs Biologie und Chemie am Paul Scherrer Institut PSI und Professor für Strukturbiologie an der ETH Zürich. In diesem Interview spricht er über die biologische Forschung am PSI und die Zukunft der Medikamentenentwicklung.
General Energy (ENE)
Einfache Experimente zeigen: so gut schützen uns Masken und andere Materialien
Spätestens seit Corona ist der Maskengebrauch auch in der Schweiz im Alltag präsent. Doch wie gut können wir uns und andere mit verschieden Materialien vor kleineren und grösseren Partikeln schützen? Das alljährlich durchgeführte PSI Feriencamp bietet Kindern einen spannenden Einblick in die faszinierende Welt der Forschung. In diesem Jahr gingen Kinder an einer Projektstation genau dieser Frage nach. Dabei untersuchten sie, wie gut verschiedene Materialien die im Labor generierten Partikel zurückhalten. Es wurden Textilmasken (im Handel erhältlich, wiederverwendbar, nicht FFP2-zertifiziert), Chirurgenmasken (Einwegmasken, FFP2-zertifiziert), Teefilter, Kaffeefilter, Papiertaschentuch und WC-Papier getestet, und es wurde klar, Maske ist nicht gleich Maske.
Online ultrahigh resolution mass spectrometry for the molecular analysis of the atmosphere
Atmospheric aerosols are considered the single largest uncertainty in assessing the human contribution to global warming and amongst the top five health risks worldwide. Our ability to investigate aerosol sources, their formation processes in the gas-phase, and their societal impacts is largely governed by our capability to measure their molecular constituents in real-time. Researchers at PSI have combined for the first time ultrahigh resolution mass spectrometry with high time resolution and sensitivity for the molecular analysis of aerosols.
Nuclear Energy and Safety Research (NES)
«Schon heute ist Elektro die richtige Wahl»
Ein Interview über Fahrzeugantriebe mit Christian Bauer, Wissenschaftler am Labor für Energiesystemanalyse des PSI und spezialisiert auf Lebenszyklus- und Nachhaltigkeitsanalysen.
Assessment of stress corrosion cracking incidents in Alloy 182 – reactor pressure vessel dissimilar metal welds
Several stress corrosion cracking (SCC) incidents recently occurred in Alloy 182 - reactor pressure vessel (RPV) dissimilar metal welds in boiling water reactors (BWR). These SCC cracks tend to grow towards the RPV due to weld microstructure and residual stress profiles and might grow into the RPV. They thus represent a serious potential safety concern. PSI has evaluated under which conditions such cracks could grow into the RPV and also developed SCC crack growth disposition curves for the RPV steels that can be used for safety assessments of such cracks. With these curves that were recently accepted as a new Code Case N-896 in the ASME Boiler and Pressure Vessel Code, sufficient safety margins could be demonstrated for such crack configurations with the current inspection intervals of the periodic in-service inspection.
GFA
Demonstration of Large Bandwidth Hard X-Ray Free-Electron Laser Pulses at SwissFEL
We have produced hard x-ray free-electron laser (FEL) radiation with unprecedented large bandwidth tunable up to 2%. The experiments have been carried out at SwissFEL, the x-ray FEL facility at the Paul Scherrer Institute in Switzerland. The bandwidth is enhanced by maximizing the energy chirp of the electron beam, which is accomplished by optimizing the compression setup. We demonstrate continuous tunability of the bandwidth with a simple method only requiring a quadrupole magnet. The generation of such broadband FEL pulses will improve the efficiency of many techniques such as x-ray crystallography and spectroscopy, opening the door to significant progress in photon science. It has already been demonstrated that the broadband pulses of SwissFEL are beneficial to enhance the performance of crystallography, and further SwissFEL users plan to exploit this large bandwidth radiation to improve the efficiency of their measurement techniques.
Generation and measurement of ultralow-emittance electron beams at SwissFEL
The emittance is a fundamental parameter of particle distributions accounting for the average spread of the particles’ positions and momenta. We have generated and characterized intense ultralow-emittance electron beams, setting new standards for electron linear accelerators. The measurements have been carried out at the SwissFEL accelerator of PSI. SwissFEL is one of the few X-ray free-electron lasers (FELs) worldwide, which are cutting-edge research instruments to investigate matter with resolutions at the level of atomic processes.