Scientific Highlights

Guguchia

A New Quantum Landscape: Coexisting High-Tc Superconductivity, Magnetism, and Complex Charge Order in LaRu3Si2.

Despite intense research on kagome superconductors, many fundamental questions remain—especially regarding the unconventional nature of their charge order and superconducting phases. These materials are rich in complexity, and to truly unravel their behavior, a broad and integrated approach is essential. In our study ...

Khasanov et al

Pressure-enhanced splitting of density wave transitions in La3Ni2O7–δ

The observation of superconductivity in La3Ni2O7–δ under pressure, following the suppression of a high-temperature density wave state, has attracted considerable attention. The nature of this density wave order was not clearly identified. Here we probe the magnetic response of the zero-pressure phase of La3Ni2O7–δ as hydrostatic pressure is applied, and find that the apparent single density wave transition at zero applied pressure splits into two. The comparison of our muon-spin rotation ...

Maimone et al

Spin-orbit control of antiferromagnetic domains without a Zeeman coupling

Encoding information in antiferromagnetic (AFM) domains is a promising solution for the ever growing demand in magnetic storage capacity. The absence of a macroscopic magnetization avoids crosstalk between different domain states, enabling ultrahigh density spintronics while being detrimental to the domain detection and manipulation. Disentangling these merits and disadvantages seemed so far unattainable. We report evidence ...

Halloran et al

Connection between f-electron correlations and magnetic excitations in UTe2

The detailed anisotropic dispersion of the low-temperature, low-energy magnetic excitations of the candidate spin-triplet superconductor UTe2 is revealed using inelastic neutron scattering. The magnetic excitations emerge from the Brillouin zone boundary at the high symmetry Y and T points and disperse along the crystallographic b-axis. In applied magnetic fields ...

Sala et al

Field-tuned quantum renormalization of spin dynamics in the honeycomb lattice Heisenberg antiferromagnet YbCl3

The basis for our understanding of quantum magnetism has been the study of elegantly simple model systems. However, even for the antiferromagnetic honeycomb lattice with isotropic spin interactions – one of the simplest model systems – a detailed understanding of quantum effects is still lacking. Here, using inelastic neutron scattering measurements of the honeycomb lattice material YbCl3, we elucidate how quantum effects renormalize ...

installation ESTIA

Swiss precision optics in Sweden

PSI has finalized the precision Selene neutron optics for the ESTIA instrument. The complex state-of-the-art guide was installed at the European Spallation Source as a Swiss in-kind delivery.

Simeth et al

Resonant Elastic X-Ray Scattering of Antiferromagnetic Superstructures in EuPtSi3

We report resonant elastic x-ray scattering of long-range magnetic order in EuPtSi3, combining different scattering geometries with full linear polarization analysis to unambiguously identify magnetic scattering contributions. At low temperatures, EuPtSi3 stabilizes type A antiferromagnetism featuring various long- wavelength modulations. For magnetic fields applied in the hard magnetic basal plane, well-defined regimes of cycloidal, conical, and fanlike superstructures may be distinguished that encompass a pocket of commensurate type A order without superstructure.

Camera team

Commissioning of the novel Continuous Angle Multi-energy Analysis spectrometer at the Paul Scherrer Institut

We report on the commissioning results of the cold neutron multiplexing secondary spectrometer CAMEA (Continuous Angle Multi-Energy Analysis) at the Swiss Spallation Neutron Source at the Paul Scherrer Institut, Switzerland. CAMEA is optimized for ...

LIN visit

The Laboratory for Neutron and Muon Instruments visits FRM II neutron research facility

Recently, the staff of the PSI’s Laboratory for Neutron and Muon Instrumentation (LIN) visited our colleagues at MLZ to learn more about the FRM II reactor and its instrumentation, as well as to discuss current and future joint projects. LIN staff was greeted with Bavarian hospitality in the form of “Weisswurst Frühstück” and then enjoyed a full tour of the facility and many fruitful discussions.

Simutis et al

Single-domain stripe order in a high-temperature superconductor

The coupling of spin, charge and lattice degrees of freedom results in the emergence of novel states of matter across many classes of strongly correlated electron materials. A model example is unconventional superconductivity, which is widely believed to arise from the coupling of electrons via spin excitations. In cuprate high-temperature superconductors, the interplay of charge and spin degrees of freedom is also reflected in a zoo of charge and spin- density wave orders that are intertwined with superconductivity ...

 

Kinder Uni Zürich

Kinderuniversität Zürich visits PSI

On November 5, 2022, the Laboratory for Neutron and Muon Instrumentation in collaboration with the Correlated Quantum Matter group at the University of Zurich carried out the workshop “Wellenspiele” (German for “Playing with Waves”) for the Kinderuniversität Zürich (“Children’s University Zurich”) for the first time. 

Rahn et al

Clarifying the fate of collective metallic quantum states

Many complex metals exhibit collective states in which electrons appear to collaborate to generate novel and frequently functional behavior. These states develop when metals are cooled down to remove the effects of thermal fluctuations, enabling collective states in which electrons move coherently through the material. These collective electronic states are of tremendous importance because they are the foundation for many quantum states of interest such as unconventional superconductivity, frustrated magnetism, hidden order, as well as topologically non-trivial and electronic-nematic states.

 

Artur Glavic NI Price

Artur Glavic received the first Instrumentation Price Neutron Research

Artur Glavic received the first Instrumentation Price Neutron Research “for his significant contributions to the development and construction of novel neutron reflectometers”. 

soft matter workshop CH-FR

SANS-LLB at PSI: keeping up with the soft matter community needs

The shutdown of the Orphée reactor at LLB (Saclay, France) and the upgrade of the SINQ neutron guide system at PSI (Villigen, Switzerland) in 2019 were the beginning of a long-term collaboration between PSI and LLB. The SANS-LLB instrument, formerly known as PA20, has travelled more than 500 km, and since 2020 is being installed at SINQ/PSI as a collaborative effort between PSI and LLB. The aim is to make a modern SANS instrument available to the soft matter neutron scattering community at the SINQ spallation source.

Choi et al

Unveiling Unequivocal Charge Stripe Order in a Prototypical Cuprate Superconductor

In the cuprates, high-temperature superconductivity, spin-density-wave order, and charge-density-wave (CDW) order are intertwined, and symmetry determination is challenging due to domain formation. We investigated the CDW in the prototypical cuprate La1.88Sr0.12CuO4 via x-ray diffraction employing uniaxial pressure as a domain-selective stimulus to establish the unidirectional nature of the CDW unambiguously.

 

Gupta et al

Microscopic evidence for anisotropic multigap superconductivity in the CsV3Sb5 kagome superconductor

The recently discovered kagome superconductor CsV3Sb5 (Tc ≃ 2.5 K) has been found to host charge order as well as a non-trivial band topology, encompassing multiple Dirac points and probable surface states. Such a complex and phenomenologically rich system is, therefore, an ideal playground for observing unusual electronic phases. Here, we report anisotropic superconducting properties of CsV3Sb5 by means of transverse-field muon spin rotation (μSR) experiments.

 

Wang et al

Uniaxial pressure induced stripe order rotation in La1.88Sr0.12CuO4

Static stripe order is detrimental to superconductivity. Yet, it has been proposed that transverse stripe fluctuations may enhance the inter-stripe Josephson coupling and thus promote superconductivity. Direct experimental studies of stripe dynamics, however, remain difficult. From a strong-coupling perspective, transverse stripe fluctuations are realized in the form of dynamic “kinks”—sideways shifting stripe sections. Here, we show how modest uniaxial pressure tuning reorganizes directional kink alignment.

 

Prof. Dr. Marc Janoschek

Waves on circular paths

Just as electrons flow through an electrical conductor, magnetic excitations can travel through certain materials. Such excitations, known in physics as "magnons" in analogy to the electron, could transport information much more easily than electrical conductors. An international research team has now made an important discovery on the way towards such components, which could be highly energy-efficient and considerably smaller.

Naumov et al

Optical Setup for a Piston-Cylinder Pressure Cell: A Two-Volume Approach

Measurement of the absolute value of the applied pressure in high-pressure muon and neutron experiments is a complicated task. It often requires the presence of a calibration material inside the sample volume, and could also cause additional time to obtain the response of the calibrant. Here we describe the use of optical calibrants for precise determination of the pressure value inside the piston-cylinder clamp cells.

 

dmcdet1.jpg

High-performance detector for DMC enters hot commissioning phase

The cold neutron diffractometer DMC at SINQ is currently undergoing major upgrades. After the recent replacement of the cold neutron guide as part of the SINQ upgrade program, the installation of the new high-performance 2D position-sensitive detector successfully entered the hot commissioning phase.

Estia ESS

The world’s most powerful neutron microscope

Researchers from the Paul Scherrer Institute PSI in Villigen have delivered a key component for the ESTIA reflectometer at the European Spallation Source ESS based in Lund, Sweden. When it comes into service in 2026, ESS will be the world’s most powerful neutron source. Switzerland is making a vital contribution to the project. Scientists from across the globe will use ESS instruments to study processes and structures on the atomic scale, advancing materials research to a new level.

SINQ hall new

SINQ - performance of the new neutron guide system

In a recent open access article in "Neutron News" the performance of the new neutron delivery system after the SINQ upgrade has been described. Neutron flux gain factors between 2 and more than 10 have been measured at the various cold neutron instruments at SINQ.....  

first ESTIA parts at ESS

First Components of ESTIA arrive at ESS

The European Spallation Source (ESS) is currently under construction in Lund, Sweden and is set to become the most powerful neutron source in Europe and world-wide. The PSI-ESS project is delivering state-of-the-art contributions to five instruments at ESS, which will be home to a suite of 15 novel instruments. Among the five PSI instruments, the reflectometer ESTIA stands out as it is delivered in its entirety by PSI ...  

SANS-LLB-3

A new small angle neutron scattering instrument arrives at SINQ from LLB

In 2018 an agreement between the Laboratoire Léon Brillouin (LLB) and Paul Scherrer Institut has been signed with the aim to jointly operate a new small angle neutron scattering (SANS) instrument at the Swiss spallation neutron source SINQ. 

Marc Janoschek

Marc Janoschek appointed Associate Professor ad personam at University of Zurich

Marc Janoschek, the head of the Laboratory for Neutron and Muon Instrumentation (LIN), was appointed as Associate Professor ad personam for experimental physics – correlated quantum materials at the University of Zurich starting February 1, 2021.

Falcon 1

FALCON - a new instrument project at SINQ

Early 2020, an agreement between the Helmholtz-Zentrum Berlin and Paul Scherrer Institut has been signed, according to which the recently commissioned Laue Diffractometer Falcon (E11) would be transferred from HZB to PSI. The purpose of this agreement was to make state-of-the-art equipment from the recently closed research reactor BER-II at HZB work for scientific community at SINQ.

Janoschek et al

Revealing Creep Motion of a Skyrmion Lattice at Ultra-Low Current Densities

Magnetic skyrmions are well-suited for encoding information because they are nano-sized, topologically stable, and only require ultra-low critical current densities jto depin from the underlying atomic lattice. Above jcskyrmions exhibit well-controlled motion, making them prime candidates for race-track memories. In thin films thermally-activated creep motion of isolated skyrmions was observed below jas predicted by theory.

 

Guguchia_PRL

Using Uniaxial Stress to Probe the Relationship between Competing Superconducting States in a Cuprate with Spin-stripe Order

We report muon spin rotation and magnetic susceptibility experiments on in-plane stress effects on the static spin-stripe order and superconductivity in the cuprate system La2−xBaxCuO4 with x = 0.115. An extremely low uniaxial stress of ∼0.1 GPa induces a substantial decrease in the magnetic volume fraction and a dramatic rise in the onset of 3D superconductivity, from ∼10 to 32 K.