Scientific Highlights
Searching for New Physics with b → sτ+τ-
In recent years, intriguing hints for the violation of lepton flavor universality (LFU) have been accumulated in semileptonic B decays, both in the charged-current transitions b → cl-ν-l (i.e., RD, RD∗, and RJ/Ψ and the neutral-current transitions b → sl+l- (i.e., RK and RK∗.
Dirac and Chiral Quantum Spin Liquids on the Honeycomb Lattice in a Magnetic Field
Motivated by recent experimental observations in α-RuCl3, we study the Κ-Γ model on the honeycomb lattice in an external magnetic field. By a slave-particle representation and variational Monte Carlo calculations, we reproduce the phase transition from zigzag magnetic order to a field-induced disordered phase. The nature of this state depends crucially on the field orientation.
Experimental signatures of emergent quantum electrodynamics in Pr2Hf2O7
In a quantum spin liquid, the magnetic moments of the constituent electron spins evade classical long-range order to form an exotic state that is quantum entangled and coherent over macroscopic length scales. Such phases offer promising perspectives for device applications in quantum information technologies, and their study can reveal new physics in quantum matter.
Structure and Interaction of Nanoparticle–Protein Complexes
The integration of nanoparticles with proteins is of high scientific interest due to the amazing potential displayed by their complexes, combining the nanoscale properties of nanoparticles with the specific architectures and functions of the protein molecules.
Quantitative 3D determination of self-assembled structures on nanoparticles using small angle neutron scattering
The ligand shell (LS) determines a number of nanoparticles’ properties. Nanoparticles’ cores can be accurately characterized; yet the structure of the LS, when composed of mixture of molecules, can be described only qualitatively (e.g., patchy, Janus, and random).
No-Go Theorem for Nonstandard Explanations of the τ → KSπντ CP Asymmetry
The CP asymmetry in τ → KSπντ, as measured by the BABAR collaboration, differs from the standard model prediction by 2.8 σ. Most nonstandard interactions do not allow for the required strong phase needed to produce a nonvanishing CP asymmetry, leaving only new tensor interactions as a possible mechanism.
A first glance at the SwissFEL x-rays wave-front
X-ray Free Electron Lasers (XFELs) combine the properties of synchrotron radiation (short wavelengths) and laser radiation (high lateral coherence, ultrashort pulse durations). These outstanding machines allow to study ultra-fast phenomena at an atomic level with unprecedented temporal resolution for answering the most intriguing open questions in biology, chemistry and physics.
Magnetic Field Control of Cycloidal Domains and Electric Polarization in Multiferroic BiFeO3
The magnetic field induced rearrangement of the cycloidal spin structure in ferroelectric monodomain single crystals of the room-temperature multiferroic BiFeO3 is studied using small-angle neutron scattering. The cycloid propagation vectors are observed to rotate when magnetic fields applied perpendicular to the rhombohedral (polar) axis exceed a pinning threshold value of ∼5T.
HERCULES School Poster Prize
Klaus Wakonig was awarded the best poster prize in the 2018 rendition of the HERCULES European School in Grenoble, France. Klaus is currently a PhD student at the CXS group at PSI, developing X-ray Fourier ptychography.
Active Sites of supported bimetallic nano-Catalysts
Dynamic Structural Changes of Active Sites in Pt–Ni Bimetallic Catalysts Revealed by a Multimodal Approach