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Xie et al

Conventional superconductivity in the doped kagome superconductor Cs(V0.86Ta0.14)3Sb5 from vortex lattice studies

A hallmark of unconventional superconductors is a complex electronic phase diagram where intertwined orders of charge-spin-lattice degrees of freedom compete and coexist. While the kagome metals such as CsV3Sb5 also exhibit complex behavior, involving coexisting charge density wave order and superconductivity, much is unclear about the microscopic origin of the superconducting pairing. We study the vortex lattice in the superconducting state of Cs(V0.86Ta0.14)3Sb5, where the Ta-doping suppresses charge order and enhances superconductivity. Using small-angle neutron scattering ...

Dutsov Pic

Anomalous spin precession systematic effects in the search for a muon EDM using the frozen-spin technique

In the paper, the international muEDM collaboration at PSI discusses systematic effects of the most sensitive measurement of the muon's electric dipole moment (EDM). Scientists from Europe are developing a prototype experiment using the frozen-spin technique (FST) to achieve unprecedented sensitivity. The FST meticulously aligns a magnetic field with a perpendicular electric field so that the muon's spin orientation always follows its momentum. This enhances the sensitivity to the muon EDM by about 3 orders of magnitude compared to the best result from the muon g-2 experiment at Brookhaven National Lab. 

The paper addresses systematic effects that could mimic an EDM signal when E- and B-fields are not perfectly aligned, adjusted, or stable over time. While most effects cancel out when reversing the magnetic field, some residual effects the specifications for the fields' uniformity, stability, and orientation,
which are challenging but achievable.

cvjetinovic

Removal of ionic and colloidal 110 mAg from radioactive wastewater using radiografted chelating adsorbents

Nuclear power plays a crucial role in a sustainable future due to its ability to generate large amounts of low-carbon electricity, which is essential for mitigating climate change. Unlike fossil fuels, nuclear energy produces minimal greenhouse gas emissions, helping to reduce the overall carbon footprint of power generation. However, the main concern is the inevitable accumulation of nuclear waste, and this needs to be properly addressed. With the anticipated increase in the number of operating nuclear power plants around the world it is essential to develop new materials and technologies for nuclear waste management. In our latest study we have developed and tested new radiografted materials as potential 110mAg adsorbents. This silver radionuclide is a very elusive contaminant in the pressurized water reactors (PWR) and represents a major problem for normal operation. Additionally, 110mAg possess a significant danger to the environment, if not removed completely from the PWR wastewater.

Ansunielli

Towards fast ptychography image reconstruction of EUV masks by deep neural networks

In this study, we explore and demonstrate a rapid method for actinic patterned EUV mask inspection based on a deep neural network (DNN) architecture which exploits a-priori information of the photomask sample. We aim to achieve fast, high-quality image reconstruction of an EUV mask by using comparatively few diffraction patterns in a formalism consistent with the ptychography approach.
We tested our prior-primed DNN method on both synthetic and experimental data, demonstrating that the sample can be reconstructed fast and with high fidelity, allowing us to map out the mask defects down to a size of about 40 nm. 

Mapanao

Design and Preclinical Evaluation of a Novel Prostate-Specific Membrane Antigen Radioligand Modified with a Transthyretin Binder

Radioligands targeting the prostate-specific membrane antigen (PSMA) are currently used in the clinics to treat patients with metastatic castration-resistant prostate cancer. Continuous investigations are, nevertheless, conducted to design new small molecule-based radioligands and improve their respective pharmacokinetic properties. Various strategies have been devised to reasonably prolong the blood circulation, which would result into enhanced tumor accumulation and radiation dose delivered to eliminate the cancer cells. The goal of this study was to investigate the influence of the incorporation of a transthyretin binder (TB-01) in the tumor uptake of the resultant PSMA-targeted radioligand.

Kiaba et al

Observation of Mermin-Wagner behavior in LaFeO3/SrTiO3 superlattices

Two-dimensional magnetic materials can exhibit new magnetic properties due to the enhanced spin fluctuations that arise in reduced dimension. However, the suppression of the long-range magnetic order in two dimensions due to long-wavelength spin fluctuations, as suggested by the Mermin-Wagner theorem, has been questioned for finite-size laboratory samples. Here we study ...

Yuan et al

Coexistence of Superconductivity and Antiferromagnetism in Topological Magnet MnBi2Te4 Films

The interface of two materials can harbor unexpected emergent phenomena. One example is interface-induced superconductivity. In this work, we employ molecular beam epitaxy to grow a series of heterostructures formed by stacking together two nonsuperconducting antiferromagnetic materials, an intrinsic antiferromagnetic topological insulator MnBi2Te4 and an antiferromagnetic iron chalcogenide FeTe.

Hu et al

Phonon promoted charge density wave in topological kagome metal ScV6Sn6

Charge density wave (CDW) orders in vanadium-based kagome metals have recently received tremendous attention, yet their origin remains a topic of debate. The discovery of ScV6Sn6, a bilayer kagome metal featuring an intriguing √3 × √3 × √3 CDW order, offers a novel platform to explore the underlying mechanism behind the unconventional CDW. Here we combine ...

cvjetinovic

Optimizing a radiochemical separation of 26Al from an acidic V-rich matrix

At the Paul Scherrer Institute (PSI), within the Isotope and Target Chemistry (ITC) group, various radiochemical methods are developed to fully separate and purify individual radionuclides. These separation methods are devised for both new experiments and for reprocessing radioactive waste from previous experiments.

Akatsuka et al (2)

Non-coplanar helimagnetism in the layered van-der-Waals metal DyTe3

Van-der-Waals magnetic materials can be exfoliated to realize ultrathin sheets or interfaces with highly controllable optical or spintronics responses. In majority, these are collinear ferro-, ferri-, or antiferromagnets, with a particular scarcity of lattice-incommensurate helimagnets of defined left- or right-handed rotation sense, or helicity. Here, we report polarized neutron scattering experiments on DyTe3, whose layered structure has highly metallic tellurium layers separated by double-slabs of dysprosium square nets...

Romankov

How the orientation of molecular single-ion magnets affects their magnetic hysteresis

Molecular single-ion magnets act as ultra-small magnets that can retain their magnetization. When organized on a well defined surface, they could allow storing information at 100 and more times higher storage densities than nowadays available. 

In the present study performed at the Swiss Light Source an international research team investigated monolayers of two very similar types of organometallic single-ion magnets, that, however, behave very differently on a flat silver surface. They link the vastly different magnetic behavior with the different orientation and adsorption configurations on the surface.

Zeng et al

Spectral evidence for Dirac spinons in a kagome lattice antiferromagnet

Emergent quasiparticles with a Dirac dispersion in condensed matter systems can be described by the Dirac equation for relativistic electrons, in analogy with Dirac particles in high-energy physics. For example, electrons with a Dirac dispersion have been intensively studied in electronic systems such as graphene and topological insulators. However, charge is not a prerequisite for Dirac fermions, and the emergence of Dirac fermions without a charge degree of freedom has been theoretically predicted to be realized in Dirac quantum spin liquids. These quasiparticles ...

Krieger et al

Weyl spin-momentum locking in a chiral topological semimetal

Spin–orbit coupling in noncentrosymmetric crystals leads to spin–momentum locking – a directional relationship between an electron’s spin angular momentum and its linear momentum. Isotropic orthogonal Rashba spin–momentum locking has been studied for decades, while its counterpart, isotropic parallel Weyl spin–momentum locking has remained elusive in experiments. Theory predicts ...

LBS Highlight 2024 April

An overview about all-solid-state batteries research activities and characterization capabilities at PSI

All-solid-state batteries (ASSBs) are forecasted to play a central role in the next generation of high energy density and safe storage devices. However, ASSBs still an immature technology and require further advancements on multiple fronts like interface (electro-)chemical and mechanical instabilities. Here, we provide an overview about PSI efforts in (i) employing advanced operando laboratory and synchrotron-based analytical methods to shed light into the various degradation mechanisms and (ii) our capabilities for interface chemical engineering.

Teaser2

Breaking the Drops

For water-cooled nuclear reactors, a loss of coolant accident constitutes one of the key scenarios to be evaluated for the design of the plant and associated safety systems. Even if these accidents are not expected to occur at all during reactor lifetime, their potential consequences include the heat up of the fuel in the reactor core. For the recovery of the plant to safe conditions, safety systems are in place to inject water in order to reflood the core and to quench the high temperature fuel. The two-phase flow behaviour during this reflooding phase is extremely complex. In particular, the prediction of the behaviour of small liquid droplets generated as the quench front propagates upwards has a significant effect on the fuel temperatures in the upper regions of the reactor core. In collaboration with the US Nuclear Regulatory Commission (NRC), we have been working to improve our modelling of the droplet behaviour and their impact on key safety parameters.

Dr. Chiara Favaretto has been honored with the Alavi-Mandell Award

Dr. Chiara Favaretto has been honored with the Alavi-Mandell Award 2024

We congratulate Dr. Chiara Favaretto for the excellent research work she did during her time at the Center for Radiopharmaceutical Sciences.

Snips of 3D spinwave image

Three-dimensional magnonics

Researchers from an international collaboration between Switzerland, Italy, and Germany have performed the first time-resolved imaging at sub-ns timescales of the three-dimensional propagation dynamics of a spinwave in a synthetic antiferromagnetic nanostructured device, opening up the possibility to investigate magnon dynamics in complex three-dimensional geometries. 

Huang et al

Surface oxidation/spin state determines oxygen evolution reaction activity of cobalt-based catalysts in acidic environment

Co-based catalysts are promising candidates to replace Ir/Ru-based oxides for oxygen evolution reaction (OER) catalysis in an acidic environment. However, both the reaction mechanism and the active species under acidic conditions remain unclear. In this study, by combining surface-sensitive soft X-ray absorption spectroscopy characterization with electrochemical analysis, we discover that the acidic OER activity of Co-based catalysts are determined by their surface oxidation/spin state. 

Abreu et al

All Two-Loop Feynman Integrals for Five-Point One-Mass Scattering

We compute the complete set of two-loop master integrals for the scattering of four massless particles and a massive one. Our results are ready for phenomenological applications, removing a major obstacle to the computation of complete next-to-next-to-leading order QCD corrections to processes such as the production of a H/Z/W boson in association with two jets at the LHC. Furthermore ...

OAM Beam

High-resolution ptychographic imaging at a seeded free-electron laser source using OAM beams

Electromagnetic waves possessing orbital angular momentum (OAM) are powerful tools for applications in optical communications, quantum technologies, and optical tweezers. Now, a consortium of collaborators in France, Italy, Slovenia, Spain, Switzerland, Sweden, and the US reports on using such beams in the extreme ultraviolet region for ptychographic imaging in the cover page article of Optica 11, Issue 3. By controlling the topological charge, the researchers achieve an improvement of 30% in image resolution.

Consiglio et al

Electron Glass Phase with Resilient Zhang-Rice Singlets in LiCu3O3

LiCu3O3 is an antiferromagnetic mixed valence cuprate where trilayers of edge-sharing Cu(II)O (3d9) are sandwiched in between planes of Cu(I) (3d10) ions, with Li stochastically substituting Cu(II). Angle-resolved photoemission spectroscopy (ARPES) and density functional theory reveal two insulating electronic subsystems that are segregated in spite of sharing common oxygen atoms: a Cu dz2/O pz derived valence band (VB) dispersing on the Cu(I) plane, and a Cu 3dx2−y2/O 2px,y derived Zhang-Rice singlet (ZRS) band dispersing on the Cu(II)O planes.

Tam et al

Flat-band hybridization between f and d states near the Fermi energy of SmCoIn5

We present high-quality angle-resolved photoemission (ARPES) and density functional theory calculations (DFT+U) of SmCoIn5. We find broad agreement with previously published studies of LaCoIn5 and CeCoIn5, confirming that the Sm 4f electrons are mostly localized. Nevertheless, our model is consistent with an additional delocalized Sm component, stemming from hybridization between the 4f electrons and the metallic bands at “hot spot” positions in the Brillouin zone. 

Delay vs. photon energy map of an ammonium iron(III) oxalate solution. The large bandwidth emission covers the full XANES range, making time-consuming monochromator scans obsolete.

Efficient transient X-ray absorption spectroscopy

By combining the unique large bandwidth emission mode of SwissFEL’s ARAMIS undulator and diffractive X-ray optics made of diamond, we have demonstrated a new method for time-resolved X-ray absorption near edge structure (XANES) spectroscopy that enables faster data acquisition and requires smaller sample quantities for high-quality data. 

Microfluidics_Aram

Microfluidic platform for in situ characterization of heterogenous catalysts

A deep understanding of active site architectures during surface-catalyzed reactions is a crucial step for the design of recyclable heterogeneous catalysts for organic synthesis. In this work, a droplet-based microfluidic setup was developed and applied to perform Suzuki-Miyaura coupling over heterogenous single-atom Pd-catalyst. 

2024 SPIE Advanced Lithography + Patterning, San Jose, California

2024 SPIE Advanced Lithography + Patterning, San Jose, California

2024 SPIE Advanced Lithography + Patterning symposium hosted leading researchers who are solving challenges in optical and EUV lithography, patterning technologies, metrology, and process integration for semiconductor manufacturing and adjacent applications. The symposium features six conference topics. 

Tipping point

The Tipping Point!

Exciting to see that some of our research on Narwhal tusk made it into an educational videogame about climate change in the Arctic and its impact on some of its inhabitants!

Amato, Morenzoni: Introduction to Muon Spin Spectroscopy

Introduction to Muon Spin Spectroscopy

Alex Amato and Elvezio Morenzoni have published a new textbook entitled 'Introduction to Muon Spin Spectroscopy: Applications to Solid State and Material Sciences'. The book is ideal for a first course in muon spin spectroscopy (µSR), comes enriched with exercises and solutions to master the subject and includes practical examples to quantify key experimental parameters.

 

Ukleev et al

Observation by SANS and PNR of pure Néel-type domain wall profiles and skyrmion suppression below room temperature in magnetic [Pt/CoFeB/Ru]10 multilayers

The study presents a unique investigation of [Pt/CoFeB/Ru]10 multilayers, revealing suppressed skyrmion phases, intricate magnetic domain structures, and Néel-type domain walls, providing crucial insights for spintronic applications.

NeelVectorMap

Spatially reconfigurable topological textures in freestanding antiferromagnetic nanomembranes

Researchers from the University of Oxford have imaged, through the use of the soft X-ray microscopy capabilities at the Swiss Light Source, spatially reconfigurable antiferromagnetic states in topologically rich free-standing nanomembranes

BFO_cycloid

Ptychographic Nanoscale Imaging of the Magnetoelectric Coupling in Freestanding Bismuth Ferrite Films

Through soft X-ray ptychographic imaging, researchers at the Swiss Light Source have directly imaged the magneto-electric coupling between the ferroelectric domain structure and the spin-cycloidal state in freestanding BiFeO3 thin films.

Hu et al

Phonon promoted charge density wave in topological kagome metal ScV6Sn6

Charge density wave (CDW) orders in vanadium-based kagome metals have recently received tremendous attention, yet their origin remains a topic of debate. The discovery of ScV6Sn6, a bilayer kagome metal featuring an intriguing √3 × √3 × √3 CDW order, offers a novel platform to explore the underlying mechanism behind the unconventional CDW. Here we combine ...

Khasanov et al

Tuning of the flat band and its impact on superconductivity in Mo5Si3−xPx

The superconductivity in systems containing dispersionless (flat) bands is seemingly paradoxical, as traditional Bardeen-Cooper-Schrieffer theory requires an infinite enhancement of the carrier masses. However, the combination of flat and steep (dispersive) bands within the multiple band scenario might boost superconducting responses, potentially explaining high-temperature superconductivity in cuprates and metal hydrides. Here, we report ...

superconductivity

Interface-induced superconductivity in magnetic topological insulators

One of the recipes for realizing topological superconductivity calls for interfacing a topological insulator with a superconductor. In a variant of that approach, Yi et al. grew a heterostructure consisting of layers of a magnetic topological insulator, (Bi,Sb)2Te3 doped with chromium, and antiferromagnetic iron telluride. Neither of these materials is superconducting, but iron telluride is a parent compound for a family of iron-based superconductors. Interfacing the layers led to the appearance of superconductivity in the presence of ferromagnetism and topological band structure. This combination of properties makes the heterostructure a promising, although not yet proven, platform for observing chiral topological superconductivity.

Paul Scherrer Institute / Procopios Constantinou

Extreme ultraviolet for scalable silicon quantum devices

Experiments at the Swiss Light Source (SLS) show the potential of extreme ultraviolet light (EUV) to make the building blocks of scalable quantum computers.

Yarema_HIghlight_NatureCom

Unravelling the amorphous structure and crystallization mechanism of GeTe phase change memory materials

Here we use in-situ high-temperature x-ray absorption spectroscopy (XAS) and theoretical calculations to quantify the amorphous structure of bulk and nanoscale GeTe. Based on XAS experiments, we develop a theoretical model of the amorphous GeTe structure, consisting of a disordered fcc-type Te sublattice and randomly arranged chains of Ge atoms in a tetrahedral coordination.

octahedra rotation

Short x-ray pulses reveal the source of light-induced ferroelectricity

Ultrafast measurements of the fluctuating atomic positions in the quantum paraelectric SrTiO3 after mid-infrared light excitation, reveal details about the creation of the material’s ferroelectric state.

Bugaev_Highlight_ML_IR

Machine Learning for Quantitative Structural Information from Infrared Spectra: The Case of Palladium Hydride

Infrared spectroscopy (IR) is a widely used technique enabling to identify specific functional groups in the molecule of interest based on their characteristic vibrational modes or the presence of a specific adsorption site based on the characteristic vibrational mode of an adsorbed probe molecule. The interpretation of an IR spectrum is generally carried out within a fingerprint paradigm by comparing the observed spectral features with the features of known references or theoretical calculations. This work demonstrates a method for extracting quantitative structural information beyond this approach by application of machine learning (ML) algorithms.

Muon sites in MnO

"Magnetostriction-Driven Muon Localization in an Antiferromagnetic Oxide" published in Phys. Rev. Lett.

A study involving PSI scientists from the LMS lab, and just published in Physical Review Letters has found that in manganese oxide, a textbook antiferromagnetic material,  the site of an implanted spin-polarized muon is not well identified, but can change due to a previously neglected effect: magnetostriction.