Scientific Highlights
Quasistatic antiferromagnetism in the quantum wells of SmTiO3/SrTiO3 heterostructures
High carrier density quantum wells embedded within a Mott insulating matrix present a rich arena for exploring unconventional electronic phase behavior ranging from non-Fermi-liquid transport and signatures of quantum criticality to pseudogap formation. Probing the proposed connection between unconventional magnetotransport and incipient electronic order within these quantum wells has however remained an enduring challenge due to the ultra-thin layer thicknesses required.
Wir starten mit 500 Millionen Myonen
Mit Myonen lassen sich Materialien für die Elektronik der Zukunft untersuchen. Die beiden PSI-Forscher Alex Amato und Thomas Prokscha erklären im Interview die Besonderheit dieser Elementarteilchen.
Macroscopic phase separation of superconductivity and ferromagnetism in Sr0.5Ce0.5FBiS2-xSex revealed by μSR
The compound Sr0.5Ce0.5FBiS2 belongs to the intensively studied family of layered BiS2 superconductors. It attracts special attention because superconductivity at Tsc = 2.8 K was found to coexist with local-moment ferromagnetic order with a Curie temperature TC = 7.5 K. Recently it was reported that upon replacing S by Se TC drops and ferromagnetism becomes of an itinerant nature.
Signatures of the topological s+- superconducting order parameter in the type-II Weyl semimetal Td-MoTe2
In its orthorhombic Td polymorph, MoTe2 is a type-II Weyl semimetal, where the Weyl fermions emerge at the boundary between electron and hole pockets. Non-saturating magnetoresistance and superconductivity were also observed in Td-MoTe2. Understanding the superconductivity in Td-MoTe2, which was proposed to be topologically non-trivial, is of eminent interest.
Coulomb spin liquid in anion-disordered pyrochlore Tb2Hf2O7
The charge ordered structure of ions and vacancies characterizing rare-earth pyrochlore oxides serves as a model for the study of geometrically frustrated magnetism. The organization of magnetic ions into networks of corner-sharing tetrahedra gives rise to highly correlated magnetic phases with strong fluctuations, including spin liquids and spin ices. It is an open question how these ground states governed by local rules are affected by disorder.
Complementary Response of Static Spin-Stripe Order and Superconductivity to Nonmagnetic Impurities in Cuprates
We report muon-spin rotation and neutron-scattering experiments on nonmagnetic Zn impurity effects on the static spin-stripe order and superconductivity of the La214 cuprates. Remarkably, it was found that, for samples with hole doping x ≈ 1/8, the spin-stripe ordering temperature Tso decreases linearly with Zn doping y and disappears at y ≈ 4%, demonstrating a high sensitivity of static spin-stripe order to impurities within a CuO2 plane.
High-Tc superconductivity in undoped ThFeAsN
Unlike the widely studied ReFeAsO series, the newly discovered iron-based superconductor ThFeAsN exhibits a remarkably high critical temperature of 30 K, without chemical doping or external pressure. Here we investigate in detail its magnetic and superconducting properties via muon-spin rotation/relaxation and nuclear magnetic resonance techniques and show that ThFeAsN exhibits strong magnetic fluctuations, suppressed below ≈35 K, but no magnetic order.
Rhea Stewart from the University of St Andrews wins an ISMS Young Scientist Award
Rhea Stewart from the University of St Andrews, UK, has been honoured with an ISMS Young Scientist Award
at the 14th International Conference on Muon Spin Rotation Relaxation and Resonance (μSR2017) in Sapporo, Japan,
for her exceptional oral presentation entitled “Anomalous Meissner Screening Probed using Low Energy Muon Spin Spectroscopy”. The Low Energy µSR
experiments have been performed at the LEM facility of the Swiss Muon Source SµS.
Thomas Prokscha new President of ISMS
Thomas Prokscha from the Laboratory for Muon Spin Spectroscopy LMU and Head of the LEM Group has been announced as the new President of the International Society for μSR Spectroscopy (ISMS)
at the 14th International Conference on Muon Spin Rotation Relaxation and Resonance (μSR2017) in Sapporo, Japan.