NUM division - Publication Highlights
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.
Crossover of high-energy spin fluctuations from collective triplons to localized magnetic excitations in Sr14−xCaxCu24O41 ladder
We studied the magnetic excitations in the quasi-one-dimensional (q-1D) ladder subsystem of Sr14−xCaxCu24O41 (SCCO) using Cu L3-edge resonant inelastic X-ray scattering (RIXS). By comparing momentum-resolved RIXS spectra with high (x = 12.2) and without (x = 0) Ca content, we track the evolution of the magnetic excitations from collective two-triplon (2 T) excitations (x = 0) to weakly- dispersive gapped modes at an energy of 280 meV (x = 12.2)...
Three PSI research facilities reveal magnetic crossover
Insights from the Swiss Muon Source, Swiss Spallation Neutron Source and Swiss Light Source reveal this coveted characteristic in an exotic layered material.
Entanglement between Muon and I > 1/2 Nuclear Spins as a Probe of Charge Environment
We report on the first example of quantum coherence between the spins of muons and quadrupolar nuclei. We reveal that these entangled states are highly sensitive to a local charge environment and thus, can be deployed as a functional quantum sensor of that environment. The quantum coherence effect was observed in vanadium intermetallic compounds which adopt the A15 crystal structure, and whose members include all technologically pertinent superconductors. Furthermore ...
Spin Density Wave versus Fractional Magnetization Plateau in a Triangular Antiferromagnet
We report an excellent realization of the highly nonclassical incommensurate spin-density wave (SDW) state in the quantum frustrated antiferromagnetic insulator Cs2CoBr4. In contrast to the well-known Ising spin chain case, here the SDW is stabilized by virtue of competing planar in-chain anisotropies and frustrated interchain exchange.
Connecting Women in Physics
Through role models and networking, the first “Women in Physics Career Symposium” helps early career researchers stay in physics
Dynamic magnetic crossover at the origin of the hidden-order in van der Waals antiferromagnet CrSBr
The van-der-Waals material CrSBr stands out as a promising two-dimensional magnet. Here, we report on its detailed magnetic and structural character- istics. We evidence that it undergoes a transition to an A-type anti- ferromagnetic state below TN ≈ 140 K with a pronounced two-dimensional character, preceded by ferromagnetic correlations within the monolayers. Furthermore, we unravel the low-temperature hidden-order within the long- range magnetically-ordered state. We find that it is associated to a slowing down of the magnetic fluctuations, accompanied by a continuous reorienta- tion of the internal field.