Scientific Highlights
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.
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
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.
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...
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 ....