Energy transition

Shifting away from nuclear energy, expanding solar and wind power, generating energy from biomass, reducing energy consumption. Switzerland is committed to becoming climate-neutral by 2050. An ambitious goal, which has become more urgent than ever due to the increasingly challenging geopolitical situation. How can a sustainable and resilient energy supply for Switzerland be established over the coming years? What's the optimal way to use renewable energy sources? What new technologies are especially promising? At PSI, researchers are seeking answers to these crucial questions.

Switching of magnetic domains reveals spatially inhomogeneous superconductivity

The interplay of magnetic and charge fluctuations can lead to quantum phases with exceptional electronic properties. A case in point is magnetically-driven superconductivity, where magnetic correlations fundamentally affect the underlying symmetry and generate new physical properties. The superconducting wavefunction in most known magnetic superconductors does not break translational symmetry.

Magnetoelastic Excitations in the Pyrochlore Spin Liquid Tb2Ti2O7

Tb2Ti2O7 is often referred to as a spin liquid as it does indeed remain in a magnetically disordered phase with spin dynamics down to 0.05 K, but this itself is a surprise since there are strong expectations of magnetic order and/or a structural distortion. However, throughout the spin liquid regime there are also strong signs of magnetoelastic coupling, leading to the suggestion that both spin and structural degrees of freedom are frustrated.

The ash formations in La Garita Caldera in Colorado, USA, are the result of eruptions of a supervolcano approximately 25 million years ago. (Photo: Courtesy of www.danielmcvey.com)

Supervolcano eruptions driven by melt buoyancy in large silicic magma chambers

Super-eruptions that dwarf all historical volcanic episodes in erupted volume and environmental impact are abundant in the geological record. Such eruptions of silica-rich magmas form large calderas. The mechanisms that trigger these supereruptions are elusive because the processes occurring in conventional volcanic systems cannot simply be scaled up to the much larger magma chambers beneath super volcanoes.

Bulk superconductivity in undoped T'-La1.9Y0.1CuO4 probed by muon spin rotation

The Meissner effect has been directly demonstrated by depth-resolved muon spin rotation measurements in high-quality thin films of the T'-structured cup rate, T'-La1.9Y0.1CuO4, to confirm bulk superconductivity (Tc ≈ 21 K) in its undoped state. The gradual expelling of an external magnetic field is observed over a depth range of ∼ 100 nm in films with a thickness of 275(15) nm, from which the penetration depth is deduced to be 466(22) nm. Based on this result, we argue that the true ground state of the “parent” compound of the n-type cuprates is not a Mott insulator but a strongly correlated metal with colossal sensitivity to apical oxygen impurities.

Production route of 44Sc

Promises of cyclotron-produced 44Sc as a diagnostic match for trivalent beta - emitters: In vitro and in vivo study of a 44Sc-DOTA-folate conjugate

Research Division Biology and Chemistry (BIO), Folate Receptor Targeting Group, Head Cristina Müller. In recent years, implementation of 68Ga-radiometalated peptides for PET imaging of cancer has attracted the attention of clinicians. Herein, we propose the use of 44Sc (half-life = 3.97 h, average β+ energy [Eβ+av] = 632 keV) as a valuable alternative to 68Ga (half-life = 68 min, Eβ+av = 830 keV) for imaging and dosimetry before 177Lu-based radionuclide therapy.

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Unique insight into carbon fibers on the nanoscale

The investigation of the mechanical properties of carbon fibers benefits from highly resolved three-dimensional density maps within representative volumes, but such images are not easily obtained with standard methods. Scientists from the Paul Scherrer Institut in collaboration with Honda R&D in Germany have recently visualized density distributions on the sub-micrometer scale within entire carbon fiber sections, revealing surprising graphite distributions within the fibers. This capability will prove useful for the systematic characterization of fibers, contributing to the development of light and robust materials at lower costs.

Polarisierte Neutronen beider Spinausrichtungen up (blau) und down (rot) gelangen unter sehr kleinen Einfallswinkeln in eine Probe. Dort werden sie an den im Magnetfeld H ausgerichteten Momenten gestreut, hier dargestellt für eine Grenzfläche. Aus den gemessenen Unterschieden der Winkelabhängigkeit für beide Spinrichtungen lässt sich ein magnetisches Tiefenprofil ableiten.

Magnetismus im Stress: Gleichzeitiger Anti- und Ferromagnetismus

Die gleichzeitige Existenz von Magnetismus und Ferroelektrizät in einem Material ist selten. Setzt sich dieser Magnetismus aus mehreren unabhängigen, magnetischen Grundzuständen zusammen, ist das ungewöhnlich. Einer schweizerisch-französischen Zusammenarbeit unter Leitung des Paul Scherrer Instituts ist es gelungen, mehrere magnetische Grundzustände in einem Material zu realisieren und detailliert zu untersuchen.

Photograph (a) and schematic cross section (b) of a typical Au–LaAlO3–SrTiO3 tunnel device. The broad gold ring (inner diameter, 160 μm) lies on top of the LaAlO3 layer, which serves as a tunnel barrier between the 2DEL and the Au. The outer ring and the centre contact of the device are Au-covered Ti contacts to the 2DEL. c, Cross-sectional high-angle annular dark-field STEM image of a Au–LaAlO3–SrTiO3 tunnel junction. The image is taken along the zone axis of the perovskite unit cells. a.u., arbitrary uni…

Interface superconductor with gap behaviour like a high-temperature superconductor

The physics of the superconducting state in two-dimensional (2D) electron systems is relevant to understanding the high-transition-temperature copper oxide superconductors and for the development of future superconductors based on interface electron systems. But it is not yet understood how fundamental superconducting parameters, such as the spectral density of states, change when these superconducting electron systems are depleted of charge carriers.