The very large number of coherent photons produced by free-electron lasers is one of the key qualities of such facilities, attracting users from numerous research fields including chemistry, biology and materials science. Recently, the two branches of PSI's free-electron laser SwissFEL each have reached new record pulse energies, packing more photons than ever before into ultrashort X-ray pulses delivered at rates of 100 Hz to the users of both beamlines.
Chiral superconductors are novel topological materials with finite angular momentum Cooper pairs circulating around a unique chiral axis, thereby spontaneously breaking time-reversal symmetry. They are rather scarce and usually feature triplet pairing: a canonical example is the chiral p-wave state realized in the A-phase of superfluid He3. Chiral triplet super- conductors are, however, topologically fragile with the corresponding gapless boundary modes only weakly protected against symmetry-preserving perturbations in contrast to their singlet counterparts. Using muon spin relaxation measurements ...
Artificial spin ices are periodic arrangements of interacting nanomagnets which allow investigating emergent phenomena in the presence of geometric frustration. Recently, it has been shown that artificial spin ices can be used as building blocks for creating functional materials, such as magnonic crystals. Scientists have now investigated the GHz dynamics in a spin ice with a chiral geometry. They found that the system possesses a rich spin-wave spectrum owing to the presence of anisotropic magnetostatic interactions. These results contribute to the understanding of GHz magnetization dynamics in spin ices and are relevant for the realization of reconfigurable magnonic crystals based on spin ices.
Revealing the predominant driving force behind symmetry breaking in correlated materials is sometimes a formidable task due to the intertwined nature of different degrees of freedom. This is the case for La2−xSrxNiO4+δ, in which coupled incommensurate charge and spin stripes form at low temperatures. Here, we use resonant x-ray photon correlation spectroscopy to study the temporal stability and domain memory of the charge and spin stripes in La2−xSrxNiO4+δ.
Frustration-driven magnetic fluctuations as the origin of the low-temperature skyrmion phase in Co7Zn7Mn6
Magnetic skyrmions in chiral cubic helimagnets, are stabilized by thermal fluctuations over a narrow region directly below the magnetic ordering temperature. Due to often being touted for use in applications, there is high demand to identify new mechanism that can expand the equilibrium skyrmion phases where these topological vortices may display an enhanced robustness against external perturbations, such as magnetic fields, due to a larger magnetic order parameter.
Polymer Electrolyte Water Electrolyzers (PEWE), due to their excellent dynamic characteristics, can provide an economical solution to the intermittent nature of new renewable sources, by converting the excess electricity into hydrogen. However, improvements in efficiency and in capital cost are still required for the large-scale deployment of this solution. In this context, we studied whether the efficiency improvements observed when using porous structures featuring a micro-porous layer (MPL) can be attributed to a better distribution of the water.
Our collaborators at the Jozef Stefan Institute – the leading author, Jan Ravnik, is now a PSI Fellow at LMN – report a ‘dynamical’ phase diagram of metastable quantum states generated via photoexcitation of the prototypical dichalcogenide material 1T-TaS2.
Probing the superconducting gap structure in the noncentrosymmetric topological superconductor ZrRuAs
The superconducting gap structure of the topological superconductor candidate ZrRuAs with a noncen- trosymmetric crystal structure has been investigated using muon-spin rotation/relaxation (μSR) measurements in transverse-field (TF) and zero-field (ZF) geometries. Magnetization, electrical resistivity, and heat capacity measurements reveal bulk superconductivity below a superconducting transition temperature Tc = 7.9(1) K.
The authors demonstrate the stability of ferromagnetic order of one unit cell thick optimally doped manganite (La0.7Ba0.3MnO3, LBMO) epitaxially grown between two layers of SrRuO3 (SRO). LBMO shows ferromagnetism even above SRO Tc. Density Functional Theory calculations help understand the reasons behind this interesting result.
At the liquid–gas phase transition in water, the density has a discontinuity at atmospheric pressure; however, the line of these first-order transitions defined by increasing the applied pressure terminates at the critical point, a concept ubiquitous in statistical thermodynamics. In correlated quantum materials, it was predicted and then confirmed experimentally that a critical point terminates the line of Mott metal–insulator transitions, which are also first-order with a discontinuous charge carrier density. In quantum spin systems, continuous quantum phase transitions have been controlled by pressure, applied magnetic field and disorder, but discontinuous quantum phase transitions have received less attention.