Recherche sur le Covid-19

The detailed anisotropic dispersion of the low-temperature, low-energy magnetic excitations of the candidate spin-triplet superconductor UTe₂ is revealed using inelastic neutron scattering. The magnetic excitations emerge from the Brillouin zone boundary at the high symmetry Y and T points and disperse along the crystallographic b-axis. In applied magnetic fields ...

Methods to prepare and characterize neutron helical waves carrying orbital angular momentum (OAM) were recently demonstrated at small-angle neutron scattering (SANS) facilities. These methods enable access to the neutron orbital degree of freedom which provides new avenues of exploration in fundamental science experiments as well as in material characterization applications. 

However, ....

Antiferromagnets with exotic spin textures promise low-power spintronic devices with extremely high operating frequencies and resistance to external perturbations. In particular, the combination of highly tunable correlated electron physics, as in complex oxides, with metallicity and antiferromagnetism is desirable but exceedingly rare. LaNiO₃, the lone example of a perovskite nickelate which is metallic across all temperatures, has long been a promising candidate, but the antiferromagnetic metallic state has remained elusive. We demonstrate the emergence  ...

The PSI Laboratory for Reactor Physics and Thermal-Hydraulics (LRT) conducts computational and experimental research with focus on the safety of nuclear reactors and systems. In recent years, it established the EPSILON program to coordinate and consolidate its research activities on nuclear space applications. Among other things, developments were initiated towards an open-source European platform for high-fidelity simulations and experiments dedicated to space nuclear reactors. Referred to as the open^SPACE platform, its underlying concepts are a) to include not only solvers but also reference simulation models as well as experimental validation data; b) to make all of these available to the broader and combined nuclear- and space communities for usage and/or further developments. Through this, the goal is thus not only to facilitate collaborative research in this area but also to enable effective support to the European Space Agency for thorough design, safety and performance evaluations of nuclear reactor systems for in-space propulsion and/or surface power. A first development phase focused on nuclear electric propulsion was proposed and retained among the two projects selected in 2023 by the Swiss National Science Foundation (SNSF) for its MARVIS call (Multidisciplinary Advanced Research Ventures in Space) and funded by the Swiss Secretariat for Research and Innovation (SERI). This project, to be conducted via four inter-connected PhD theses, was launched in October 2024 and this marks thus a key milestone for the propulsion of PSI nuclear research towards space.

We experimentally study the evolution of the magnetic moment 𝑚 and exchange interaction 𝐽 as a function of hydrostatic pressure in the zero-field helimagnetic phase of the strongly correlated electron system MnSi. The suppression of magnetic order at ≈1.5  GPa is shown to arise from the 𝐽 collapse and not from a quantum fluctuations induced reduction of 𝑚. Our work provides benchmarks ...