Scientific Highlights
Shedding light on the origins of high-Tc superconductivity in bismuth oxides
Researchers have overcome a number of challenges in order to employ an advanced probe in the study of an unusual material, barium bismuth oxide (BaBiO3) – an insulating parent compound of a family of high-temperature superconductors known since the late 80s. In order to finally realize the experiments, the researchers grew and studied thin films of the material completely in situ under ultrahigh vacuum conditions. The results show that superconductivity in bismuth oxides emerges out of a novel insulating phase, where hole pairs located on combinations of the oxygen orbitals are coupled with distortions of the crystal lattice.
Ferromagnetic Quantum Critical Point Avoided by the Appearance of Another Magnetic Phase in LaCrGe3 under Pressure
The temperature-pressure phase diagram of the ferromagnet LaCrGe3 is determined for the first time from a combination of magnetization, muon-spin-rotation, and electrical resistivity measurements. The ferromagnetic phase is suppressed near 2.1 GPa, but quantum criticality is avoided by the appearance of a magnetic phase, likely modulated, AFMQ.
Muon polarization in the MEG experiment: predictions and measurements
The MEG experiment makes use of one of the world’s most intense low energy muon beams, in order to search for the lepton flavour violating process μ+→e+γ . We determined the residual beam polarization at the thin stopping target, by measuring the asymmetry of the angular distribution of Michel decay positrons as a function of energy. The initial muon beam polarization at the production is predicted to be Pμ=−1Pμ=−1 by the Standard Model (SM) with massless neutrinos.
Momentum-Resolved Electronic Structure of the High-Tc Superconductor Parent Compound BaBiO3
We investigate the band structure of BaBiO3, an insulating parent compound of doped high-Tc superconductors, using in situ angle-resolved photoemission spectroscopy on thin films. The data compare favorably overall with density functional theory calculations within the local density approximation, demonstrating that electron correlations are weak. The bands exhibit Brillouin zone folding consistent with known BiO6 breathing distortions.
Therapeutic drug monitoring in sub-nanoliter volumes
A promising system for painless and minimally-invasive therapeutic drug monitoring has been demonstrated. The proposed device combines biofunctionalized hollow microneedles with an optofluidic system to measure drug concentrations in volumes as small as 0.6 nL.
Magnetoelectroelastic control of magnetism
X-ray magnetic circular dichroism at the Co L3,2 edges measured at the X-Treme beamline, SLS and at the Advanced Light Source, evidence that three distinct electric field driven remanent magnetization states can be set in the Co film at room temperature. Ab initio density functional theory calculations unravel the relative contributions of both strain and charge to the observed magnetic anisotropy changes illustrating magnetoelectroelastic coupling at artificial multiferroic interfaces.
Controlling Quantum States Atom by Atom
A method to precisely alter the quantum mechanical states of electrons within an array of quantum boxes has been developped by an international consortium also including PSI. The method can be used to investigate the interactions between various types of atoms and electrons, which is essential for future quantum technologies.
Single shot grating interferometry demonstrated using direct conversion detection
Researchers at the Paul Scherrer Institute's Swiss Light Source in Villigen, Switzerland, have developed an X-ray grating interferometry setup which does not require an analyzer grating, by directly detecting the fringes generated by the phase grating with a high resolution detector. The 25um pitch GOTTHARD microstrip detector utilizes a direct conversion sensor in which the charge generated from a single absorbed photon is collected by more than one channel. Therefore it is possible to interpolate to achieve a position resolution finer than the strip pitch.
Itinerant and Localized Magnetization Dynamics in Antiferromagnetic Holmium
Resonant magnetic scattering performed at the x-ray free electron laser facility LCLS (USA) has been used to investigate the magnetization dynamics of elemental Holmium. It is found that the demagnetization of conduction electrons and localized 4f magnetic moments have the same temporal evolution showing a strong coupling between the different magnetic moments.
First light from the SwissFEL Experimental Laser
The SwissFEL Experimental Laser 1 has successfully been delivered and installed in a temporary laser lab by Coherent, from where it will be moved to SwissFEL by end of 2016. The pre-installation in the temporary laser lab allows to become acquainted with the system, to set up a full monitoring and diagnostics system and to debug potential problems in the next months.