NUM division - Publication Highlights
Emergence of spin-orbit coupled ferromagnetic surface state derived from Zak phase in a nonmagnetic insulator FeSi
FeSi is a nonmagnetic narrow-gap insulator, exhibiting peculiar charge and spin dynamics beyond a simple band structure picture. Those unusual features have been attracting renewed attention from topological aspects. Although the surface conduction was demonstrated according to size-dependent resistivity in bulk crystals, its topological characteristics and consequent electromagnetic responses remain elusive. Here, we demonstrate ...
Unconventional Pressure Dependence of the Superfluid Density in the Nodeless Topological Superconductor α-PdBi2
We investigated the superconducting properties of the topological superconductor α-PdBi2 at ambient and external pressures up to 1.77 GPa using muon spin rotation experiments. The ambient pressure measurements evince a fully gapped s-wave superconducting state in the bulk of the specimen. Alternating current magnetic susceptibility and muon spin rotation measurements manifest a continuous suppression of Tc with increasing pressure.
CrI3 has raised as an important system to the emergent field of two-dimensional van der Waals magnetic materials. However, it is still unclear why CrI3 which has a ferromagnetic rhombohedral structure in bulk, changed to anti-ferromagnetic monoclinic at thin layers. Here we show that this behaviour is due to the coexistence of both monoclinic and rhombohedral crystal phases followed by three magnetic transitions at TC1 = 61 K, TC2 = 50 K and TC3 = 25 K.
Quantum spin liquids are exotic states of matter that form when strongly frustrated magnetic interactions induce a highly entangled quantum paramagnet far below the energy scale of the magnetic interactions. Three-dimensional cases are especially challenging due to the significant reduction of the influence of quantum fluctuations. Here, we report the magnetic characterization of K2Ni2(SO4)3 forming a three-dimensional network of Ni2+ spins.
Materials with strongly correlated electrons often exhibit interesting physical properties. An example of these materials is the layered oxide perovskite Sr2RuO4, which has been intensively investigated due to its unusual properties. Whilst the debate on the symmetry of the superconducting state in Sr2RuO4 is still ongoing, a deeper understanding of the Sr2RuO4 normal state appears crucial as this is the background in which electron pairing occurs. Here, by using low-energy muon spin spectroscopy we discover the existence of surface magnetism in Sr2RuO4 in its normal state.
A specialSciPost volume, entitled “Review of Particle Physics at PSI”, has recently been completed.
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 ...
The crystal structure and magnetic correlations in triangular antiferromagnet FeGa2S4 are studied by x-ray diffraction, magnetic susceptibility, neutron diffraction, and neutron inelastic scattering. We report significant mixing at the cation sites and disentangle magnetic properties dominated by major and minor magnetic sites.