Transition énergétique

LaTiO_xN_y oxynitride thin films are employed to study the surface modifications at the solid- liquid interface that occur during photoelectrocatalytic water splitting. Neutron reflectometry and grazing incidence x-ray absorption spectroscopy were utilised to distinguish between the surface and bulk signals, with a surface sensitivity of 3 nm.

Microcalcifications are a common sign in mammography. For example, in 90% of ductal carcinoma in situ microcalcifications are the first and unique sign indicating the presence of the lesion. Nevertheless, up to around 50% of the resulting biopsies reveal a benign lesion, a 'false positive'. Researchers were able to show now that breast microcalcifications detected in tumors have specific chemical and crystalline features different from those observed in benign samples. Moreover, microcalcifications detected in tumors but located outside the lesion show malignant features too. This indicates that cancer influences the surrounding tissue even if it exhibits apparently healthy morphological features. These results indicate that the biochemical differences between benign and malignant microcalcifications can be potentially identified by light-based tools, able to investigate microcalcifications inside the breast without performing biopsies.

Update of the SLS MX beamline operation during the COVID-19 period

We monitored the dynamic structure of the active sites in a catalyst containing highly dispersed copper-oxo species on ceria during low-temperature CO oxidation using time-resolved X-ray absorption spectroscopy. We quantitatively demonstrate that the CO oxidation mechanism below 90 °C involves an oxygen intermediate strongly bound to the active sites as well as the redox activity of Cu²⁺/Cu⁺ and Ce⁴⁺/Ce³⁺ couples.

Elucidating the role of different degrees of freedom in a phase transition is crucial in the comprehension of complex materi- als. A phase transformation that attracts significant interest is the insulator-to-metal transition of Mott insulators, in which the electrons are thought to play the dominant role. Here, we use ultrafast laser spectroscopy and theoretical calculations ....

With experimental work demonstrating that the correlated ground state of the pyrochlore system Ce₂Sn₂O₇ is a quantum liquid of magnetic octupoles, an international team led by PSI researcher Romain Sibille establishes a fundamentally new state of matter: higher-rank multipole ice.

With experimental work demonstrating that the correlated ground state of the pyrochlore system Ce₂Sn₂O₇ is a quantum liquid of magnetic octupoles, an international team led by PSI researcher Romain Sibille establishes a fundamentally new state of matter: higher-rank multipole ice.

The TOMCAT beamline at the Swiss Light Source specializes in rapid high-resolution 3-dimensional tomographic microscopy measurements with a strong focus on biomedical imaging. The team has recently developed a technique to acquire micrometer-scale resolution datasets on the entire lung structure of a juvenile rat in its fresh natural state within the animal’s body and without the need for any fixation, staining or other alteration that would affect the observed structure (E. Borisova et al., 2020, Histochem Cell Biol).

With experimental work demonstrating that the correlated ground state of the pyrochlore system Ce₂Sn₂O₇ is a quantum liquid of magnetic octupoles, an international team led by PSI researcher Romain Sibille establishes a fundamentally new state of matter: higher-rank multipole ice.

We show that hybrid MnO_x/C₆₀ heterojunctions can be used to design a storage device for spin-polarized charge: a spin capacitor. Hybridization at the carbon-metal oxide interface leads to spin-polarized charge trapping after an applied voltage or photocurrent. Strong electronic structure changes, including a 1-eV energy shift and spin polarization in the C60 lowest unoccupied molecular orbital, are then revealed by x-ray absorption spectroscopy, in agreement with density functional theory simulations.

A collaboration of scientists from the ETH Zürich and the Paul Scherrer Institute successfully demonstrated the all-electric operation of a magnetic domain-wall based NAND logic gate, paving the way towards the development of logic applications beyond the conventional metal-oxide semiconductor technology. The work has been published in the journal Nature.

In this work, published on the front cover page of Advanced Materials, an international collaboration of Italian, American, and Swiss scientists demonstrated a novel concept for the generation and manipulation of spin waves, paving the way towards the development of magnonic nano-processors.

Can a skyrmion-based device be used to read a handwritten text? In this work, an international scientist collaboration led by the Korea Institute of Technology and the IBM Watson research center could provide a first answer to this question by fabricating a proof-of-principle single-neuron artificial neural network, using X-ray magnetic microscopy at the Swiss Light Source to investigate its performances.

Detailed understanding of charge diffusion processes in a lithium-ion battery is crucial to enable its systematic improvement. Experimental investigation of diffusion at the interface between active particles and the electrolyte is challenging but warrants investigation as it can introduce resistances that, for example, limit the charge and discharge rates. Here, we show an approach to study diffusion at interfaces using muon spin spectroscopy.

Spin-based logic architectures provide nonvolatile data retention, near-zero leakage, and scalability, extending the technology roadmap beyond complementary metal–oxide–semiconductor logic. Architectures based on magnetic domain walls take advantage of the fast motion, high density, non-volatility and flexible design of domain walls to process and store information. Such schemes, however, rely on domain-wall manipulation and clocking using an external magnetic field, which limits their implementation in dense, large-scale chips.

Topological properties of materials are of fundamental as well as practical importance. Of particular interest are unconven- tional superconductors that break time-reversal symmetry, for which the superconducting state is protected topologically and vortices can host Majorana fermions with potential use in quantum computing. However, in striking contrast to the unconventional A phase of superfluid ³He where chiral symmetry was directly observed, .....

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.