Scientific Highlights
Chiral singlet superconductivity in the weakly correlated metal LaPt3P
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 ...
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.
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.
Spin-singlet to triplet Cooper pair converter interface
Combining magnetic and superconducting functionalities enables lower energy spin transfer and magnetic switching in quantum computing and information storage, owing to the dissipationless nature of quasi-particle mediated supercurrents. Here, we put forward a system where emergent spin-ordering and diffusion of Cooper pairs are achieved at a non-intrinsically magnetic nor superconducting metallo-molecular interface.
15th International Conference on Muon Spin Rotation postponed to 2022
Because of the coronavirus situation, the 15th International Conference on Muon Spin Rotation, Relaxation and Resonance (µSR2020) has been postponed to 2022, Aug 28 - Sep 02.
Information for SµS Users March 2021
Despite some limitations due to the Covid crisis the shutdown works at SµS have proceeded as planned so far, and the µSR instruments will be ready for operation on April 12, when HIPA operation is foreseen. However, as Swiss and foreign travel restrictions apply (https://www.psi.ch/en/useroffice/news/new-coronavirus-recommendations-for-travellers) it is not yet clear how user experiments at SµS will be conducted in the upcoming beam period. We will update information about this on our webpage as soon as possible.
Split superconducting and time-reversal symmetry-breaking transitions in Sr2RuO4 under stress
Strontium ruthenate (Sr2RuO4) continues to present an important test of our understanding of unconventional superconductivity, because while its normal-state electronic structure is known with precision, its superconductivity remains unexplained. There is evidence that its order parameter is chiral, but reconciling this with recent observations of the spin part of the pairing requires an order parameter that is either finely tuned or implies a new form of pairing. Therefore, a definitive resolution of whether the superconductivity of Sr2RuO4 is chiral is important for the study of superconductivity.
Quantum spin-liquid states in an organic magnetic layer and molecular rotor hybrid
A better understanding of quantum spin liquids (QSLs), where spin dimer configurations are fluctuating even at the low- est temperatures, could be of use in quantum information, in superconducting or other technologies. This macroscopic collective state typically arises from geometrical frustration or low dimensionality. In the layered EDT-BCO, we report a QSL state, which is generated, on different bases, with the intrinsic disorder.
Re(1−x)Mox as an ideal test case of time-reversal symmetry breaking in unconventional superconductors
Non-centrosymmetric superconductors (NCSCs) are promising candidates in the search for unconventional and topological superconductivity. The α-Mn-type rhenium-based alloys represent excellent examples of NCSCs, where spontaneous magneticfields, peculiar to time-reversal symmetry (TRS) breaking, have been shown to develop in the superconducting phase. By converse, TRS is preserved in many other isostructural NCSCs, thus leaving the key question about its origin fully open. Here, we consider ...