News

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.

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 ...

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.

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 ...

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.

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...

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.

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 ...

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 ...

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.

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

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. 

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. 

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 ...

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 d_z²/O p_z derived valence band (VB) dispersing on the Cu(I) plane, and a Cu 3d_x²−y²/O 2p_x,y derived Zhang-Rice singlet (ZRS) band dispersing on the Cu(II)O planes.

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. 

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. 

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!

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.

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.

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

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.

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 ...

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 ...

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.

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.

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.

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.

Magnetostriction results from the coupling between magnetic and elastic degrees of freedom. Though it is associated with a relatively small energy, we show that it plays an important role in determining the site of an implanted muon, so that the energetically favorable site can switch on crossing a magnetic phase transition. This surprising effect is demonstrated in the cubic rocksalt antiferromagnet MnO which undergoes a magnetostriction-driven rhombohedral distortion at the Néel temperature T_N = 118 K. Above T_N ...

On January 23rd, 2024, first "Swedish" X-ray light was delivered to the SOPHIE endstation, currently installed at the SoftiMAX beamline of the MaxIV light source.

n2EDM is the current state of the art experiment carrying out a high-precision search for an electric dipole moment of the neutron at the ultra-cold neutron source of PSI. In order to reach it’s incredible precision of 10^-27 e cm, a stable and uniform magnetic environment is critical. Thus, shielding the experiment from external magnetic flux and preparing a pristine magnetic environment is crucial. To achieve this, n2EDM uses both passive and active magnetic shielding components. External, or residual, magnetic field contributions must be near-zero, and can be achieved via “degaussing” the experiment’s passive magnetic shielding. Degaussing reduces, ideally “erases”, the residual magnetization of a material. In this work, we greatly improved the degaussing procedure of n2EDM, reducing the residual magnetic field by a factor of two, improving its uniformity, and all while taking less time and dissipating less heat.

Synchrotron X-ray diffraction sheds  light on laser-induced local recrystallization .

In quantum magnetic materials, ordered phases induced by an applied mag- netic field can be described as the Bose-Einstein condensation (BEC) of mag- non excitations. In the strongly frustrated system SrCu₂(BO₃)₂, no clear magnon BEC could be observed, pointing to an alternative mechanism, but the high fields required to probe this physics have remained a barrier to detailed investigation.Here we exploit the first purpose-built high-field neutron scattering facility to measure ...

Pt-FeO_x(OH)_y interface with enhanced activity for PROX is generated via strong metal-support interaction. Increase in the degree of hydroxylation of Pt-FeO_x(OH)_y interface enhances the rate of PROX mediated by active Fe²⁺ species.