NUM division - Publication Highlights
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 ...
Spin-orbit driven superconducting proximity effects in Pt/Nb thin films
Manipulating the spin state of thin layers of superconducting material is a promising route to generate dissipationless spin currents in spintronic devices. Approaches typically focus on using thin ferromagnetic elements to perturb the spin state of the superconducting condensate to create spin-triplet correlations. We have investigated simple structures that generate spin-triplet correlations without using ferromagnetic elements.
Unconventional charge order and superconductivity in kagome-lattice systems as seen by muon-spin rotation
Kagome lattices are intriguing and rich platforms for studying the intertwining of topology, electron correlation, and magnetism. These materials have been subject to tremendous experimental and theoretical studies not only due to their exciting physical properties but also as systems that may solve critical technological problems. We will review recent experimental progress on superconductivity and magnetic fingerprints of charge order in several kagome-lattice systems from the local-magnetic probe point of view by utilizing muon-spin rotation under extreme conditions, i.e., hydrostatic pressure, ultra low temperature and high magnetic field.
Strong phonon softening and avoided crossing in aliovalence-doped heavy-band thermoelectrics
Aliovalent doping is a way to optimize the electrical properties of semiconductors, but its impact on the phonon structure and propagation is seldom considered properly. Here we show that aliovalent doping can be much more effective in reducing the lattice thermal conductivity of thermoelectric semiconductors than the commonly employed isoelectronic alloying strategy. We demonstrate ...
Direct observation of exchange anisotropy in the helimagnetic insulator Cu2OSeO3
The helical magnetic structures of cubic chiral systems are well explained by the competition among Heisen- berg exchange, Dzyaloshinskii-Moriya interaction, cubic anisotropy, and anisotropic exchange interaction (AEI). Recently, the role of the latter has been argued theoretically to be crucial for the low-temperature phase diagram of the cubic chiral magnet Cu2OSeO3, which features tilted conical and disordered skyrmion states for a specific orientation of the applied magnetic field (μ0H⃗ ∥ [001]). In this study ...
Bronze Age arrowhead is made of meteoritic iron
With the help of muons, PSI researchers were able to determine the origin of the material used for an arrowhead.
Emergent Magnetism with Continuous Control in the Ultrahigh-Conductivity Layered Oxide PdCoO2
The current challenge to realizing continuously tunable magnetism lies in our inability to systematically change properties, such as valence, spin, and orbital degrees of freedom, as well as crystallographic geometry. Here, we demonstrate that ferromagnetism can be externally turned on with the application of low-energy helium implantation and can be subsequently erased and returned to the pristine state via annealing.
Mystery of microgels solved
Researchers at PSI and the University of Barcelona can explain the strange shrinking of microgels experimentally.
Coupling of magnetic phases at nickelate interfaces
In this paper we present a model system built out of artificially layered materials, allowing us to understand the interrelation of magnetic phases with the metallic-insulating phase at long length scales, and enabling new strategies for the design and control of materials in devices. The artificial model system consists of superlattices made of SmNiO3 and NdNiO3 layers, – two members of the fascinating rare earth nickelate family, having different metal-to-insulator and magnetic transition temperatures. By combining two complementary techniques ....