Scientific Highlights: Research Division "Research with Neutrons and Muons"
Muonic X-rays peer into brooch from Roman city
Using Muon Induced X-ray Emission, researchers could reveal the inner composition of a knob-bow fibula, excavated at Augusta Raurica in northern Switzerland.
How to squash things carefully
A new in situ uniaxial pressure cell at Paul Scherrer Institute PSI gives scientists unrivalled control to tweak quantum materials microscopically and tune their properties.
Visualizing Higher-Fold Topology in Chiral Crystals
Novel topological phases of matter are fruitful platforms for the discovery of unconventional electromagnetic phenomena. Higher-fold topology is one example, where the low-energy description goes beyond standard model analogs. Despite intensive experimental studies, conclusive evidence remains elusive for the multigap topological nature of higher-fold chiral fermions. In this Letter, we leverage a combination of fine-tuned chemical engineering and photoemission spectroscopy with photon energy contrast to discover the higher-fold topology of a chiral crystal.
Commissioning of the novel Continuous Angle Multi-energy Analysis spectrometer at the Paul Scherrer Institut
We report on the commissioning results of the cold neutron multiplexing secondary spectrometer CAMEA (Continuous Angle Multi-Energy Analysis) at the Swiss Spallation Neutron Source at the Paul Scherrer Institut, Switzerland. CAMEA is optimized for ...
More light in the darkness
At PSI, researchers want to fill the missing gaps in the Standard Model of particle physics with the help of the large research facilities.
Unconventional superconductivity found in kagome metal
Physicists using muon spin spectroscopy at PSI make the missing link between their recent breakthrough in Nature and unconventional superconductivity
Fate of charge order in overdoped La-based cuprates
In high-temperature cuprate superconductors, stripe order refers broadly to a coupled spin and charge modulation with a commensuration of eight and four lattice units, respectively. How this stripe order evolves across optimal doping remains a controversial question. Here we present a systematic resonant inelastic x-ray scattering study of weak charge correlations in La2−xSrxCuO4 and La1.8−xEu0.2SrxCuO4. Ultra high energy resolution experiments demonstrate the importance of the separation of inelastic and elastic scattering processes.
Further optimising car brakes
Research scientists at PSI and ANAXAM use neutrons to look inside brake callipers and identify potential ways of reducing CO2 emissions.
A two-part upgrade for the proton accelerator
A two-part upgrade is planned for HIPA from 2025 to 2028. Preparations are already under way.
Making sense of the muon’s misdemeanours
An exotic atom called muonium could explain why muons won’t stick to the rules, believe researchers using the Swiss Muon Source at Paul Scherrer Institute PSI.
Upgraded pixel detector back in action at CERN
Built at Paul Scherrer Institute, the detector forms the heart of the CMS experiment. It is producing data again following an upgrade during the LHC shutdown.
Single-domain stripe order in a high-temperature superconductor
The coupling of spin, charge and lattice degrees of freedom results in the emergence of novel states of matter across many classes of strongly correlated electron materials. A model example is unconventional superconductivity, which is widely believed to arise from the coupling of electrons via spin excitations. In cuprate high-temperature superconductors, the interplay of charge and spin degrees of freedom is also reflected in a zoo of charge and spin- density wave orders that are intertwined with superconductivity ...
Perspective on muon-spin rotation/relaxation under hydrostatic pressure
Pressure, together with temperature, electric, and magnetic fields, alters the system and allows for the investigation of the fundamental prop- erties of matter. Under applied pressure, the interatomic distances shrink, which modifies the interactions between atoms and may lead to the appearance of new (sometimes exotic) physical properties, such as pressure-induced phase transitions; quantum critical points; new structural, magnetic, and/or superconducting states; and changes of the temperature evolution and symmetry of the order parameters...
Silver Medal in Electronics for Mario Liechti
PSI electronics technician Mario Liechti comes in second place at the world championships for non-academic professions.
Emergence of spinons in layered trimer iridate Ba4Ir3O10
Spinons are well-known as the elementary excitations of one-dimensional antiferromagnetic chains, but means to realize spinons in higher dimensions is the subject of intense research. Here, we use resonant x-ray scattering to study the layered trimer iridate Ba4Ir3O10, which shows no magnetic order down to 0.2 K. An emergent one-dimensional spinon continuum is observed that can be well-described by XXZ spin-1/2 chains with magnetic exchange of ∼55 meV and a small Ising-like anisotropy. With 2% isovalent Sr doping ...
Graphene’s magic in a magnet
Neutron scattering reveals rich magnetic topology in the magnetic equivalent of graphene.
Clarifying the fate of collective metallic quantum states
Many complex metals exhibit collective states in which electrons appear to collaborate to generate novel and frequently functional behavior. These states develop when metals are cooled down to remove the effects of thermal fluctuations, enabling collective states in which electrons move coherently through the material. These collective electronic states are of tremendous importance because they are the foundation for many quantum states of interest such as unconventional superconductivity, frustrated magnetism, hidden order, as well as topologically non-trivial and electronic-nematic states.
Discovery of Charge Order and Corresponding Edge State in Kagome Magnet FeGe
Kagome materials often host exotic quantum phases, including spin liquids, Chern gap, charge density wave, and superconductivity. Existing scanning microscopy studies of the kagome charge order have been limited to nonkagome surface layers. Here, we tunnel into the kagome lattice of FeGe to uncover features of the charge order. Our spectroscopic imaging identifies a 2 × 2 charge order in the magnetic kagome lattice, resembling that discovered in kagome superconductors. Spin mapping across steps of unit cell height demonstrates the existence of spin-polarized electrons with an antiferromagnetic stacking order.
Two types of charge order with distinct interplay with superconductivity in the kagome material CsV3Sb5
The kagome metals of the family AV3Sb5, featuring a unique structural motif, harbor an array of intriguing phenomena such as chiral charge order and superconductivity. CsV3Sb5 is of particular interest because it displays a double superconducting dome in the region of the temperature-pressure phase diagram where charge order is still present. However, the microscopic origin of such an unusual behavior remains an unsolved issue. Here, to address it, we combine high-pressure, low-temperature muon spin relaxation/rotation with first-principles calculations. We observe ....
The gold medal and a handshake from the Federal Councillor
SwissSkills names PSI electronics technician Melvin Deubelbeiss the best apprenticeship graduate in his field.