A5032008379- Physics of Superconductivity and Magnetism
- Rare-earth and actinide compounds
- Iron-based superconductors research
- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Advanced X-ray Imaging Techniques
- Magnetic Properties of Alloys
- Magnetic properties of thin films
- Advanced Chemical Physics Studies
- Parallel Computing and Optimization Techniques
- Atomic and Subatomic Physics Research
- Advanced Data Storage Technologies
- High-pressure geophysics and materials
- Security and Verification in Computing
- X-ray Diffraction in Crystallography
- Quantum and electron transport phenomena
- Particle Accelerators and Free-Electron Lasers
- Context-Aware Activity Recognition Systems
- Inorganic Chemistry and Materials
- Crystallography and Radiation Phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Embedded Systems and FPGA Applications
- Thermoelastic and Magnetoelastic Phenomena
- Laser-Matter Interactions and Applications
- Tracheal and airway disorders
Paul Scherrer Institute
2014-2024
Karlsruhe Institute of Technology
2024
Brown University
2021
Stanford University
1973-2017
SLAC National Accelerator Laboratory
2014-2017
University of Alberta
2016
ETH Zurich
2008-2015
Universität Ulm
2011-2012
The University of Sydney
2010-2012
University Children's Hospital Zurich
2007
Charge density wave (CDW) correlations have recently been shown to universally exist in cuprate superconductors. However, their nature at high fields inferred from nuclear magnetic resonance is distinct that measured by x-ray scattering zero and low fields. Here we combine a pulsed magnet with an free electron laser characterize the CDW YBa2Cu3O6.67 via up 28 Tesla. While zero-field order, which develops below T ~ 150 K, essentially two-dimensional, lower temperature beyond 15 Tesla, another...
A deeper look into iron selenide In the past 10 years, iron-based superconductors have created more puzzles than they helped resolve. Some of most fundamental outstanding questions are how strong interactions and what electron pairing mechanism is. Now two groups made contributions toward resolving these in intriguing compound (FeSe) (see Perspective by Lee). Gerber et al. used photoemission spectroscopy coupled with x-ray diffraction to find that FeSe has a very sizable electron-phonon...
The existence of charge density wave (CDW) correlations in cuprate superconductors has now been established. However, the nature ground state order remained uncertain because disorder and presence superconductivity typically limit CDW correlation lengths to a dozen unit cells or less. Here we explore YBa2Cu3Ox (YBCO) ortho-II ortho-VIII crystals, which belong cleanest available family, at magnetic fields excess resistive upper critical field (Hc2) where is heavily suppressed. We find an...
Abstract Tuning of electronic density-of-states singularities is a common route to unconventional metal physics. Conceptually, van Hove are realized only in clean two-dimensional systems. Little attention has therefore been given the disordered (dirty) limit. Here, we provide magnetotransport study dirty metamagnetic system calcium-doped strontium ruthenate. Fermi liquid properties persist across transition, but with an unusually strong variation Kadowaki-Woods ratio. This revealed by...
We have studied the magnetic order inside superconducting phase of ${\mathrm{CeCoIn}}_{5}$ for fields along $[1\text{ }0\text{ }0]$ crystallographic direction using neutron diffraction. find a spin-density wave with an incommensurate modulation $\mathbf{Q}=(q,q,1/2)$ and $q=0.45(1)$, which within our experimental uncertainty is indistinguishable from found applied }\ensuremath{-}1\text{ }0]$. The thus modulated lines nodes ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ parameter, suggesting that it...
Abstract Ultrafast light pulses can modify electronic properties of quantum materials by perturbing the underlying, intertwined degrees freedom. In particular, iron-based superconductors exhibit a strong coupling among nematic fluctuations, spins and lattice, serving as playground for ultrafast manipulation. Here we use time-resolved X-ray scattering to measure lattice dynamics photoexcited BaFe 2 As . On optical excitation, no signature an change crystal symmetry is observed, but oscillates...
We present Barrelfish/DC, an extension to the Barrelfish OS which decouples physical cores from a native kernel, and furthermore kernel itself rest of application state. In code on any core can be quickly replaced, state moved between cores, added removed system transparently applications processes, continue execute.Barrelfish/DC is multikernel with two novel ideas: use boot drivers abstract as regular devices, partitioned capability for memory management externalizes core-local state.We...
We investigated the crystal structure and lattice excitations of ternary intermetallic stannide ${\mathrm{Ca}}_{3}{\mathrm{Ir}}_{4}{\mathrm{Sn}}_{13}$ using neutron x-ray scattering techniques. For $T>{T}^{*}\ensuremath{\approx}38$ K, diffraction data can be satisfactorily refined space group $Pm\overline{3}n$. Below ${T}^{*}$, is modulated with a propagation vector $\stackrel{P\vec}{q}=(1/2,1/2,0)$. This may arise from merohedral twinning in which three tetragonal domains overlap to mimic...
Levobupivacaine in combination with sufentanil may be used for labour or postoperative regional analgesia. The risk of bacterial growth within these contained solutions several hours at room temperature is unknown. We investigated the vitro antimicrobial effect levobupivacaine and against common micro-organisms encountered during anaesthesia.Standardized suspensions Staphylococcus aureus, epidermidis Escherichia coli were incubated 1, 3, 6 24 h 25 degrees C, saline (as control), 0.5 0.75...
We report on muon spin rotation ($\ensuremath{\mu}$SR) studies of the superconducting and magnetic properties ternary intermetallic stannide Ca${}_{3}$Ir${}_{4}$Sn${}_{13}$. This material has recently been focus intense research activity due to a proposed interplay ferromagnetic fluctuations superconductivity. In temperature range $T=1.6$--200 K, we find that zero-field relaxation rate is very low does not provide evidence for $\ensuremath{\mu}$SR time scale. The field-induced magnetization...
We investigated the doping dependence of magnetic excitations in lightly doped cuprate La2-xSrxCuO4 via combined studies resonant inelastic x-ray scattering (RIXS) at Cu L3-edge and theoretical calculations. With increasing doping, magnon dispersion is found to be essentially unchanged, but spectral width broadens weight varies differently different momenta. Near Brillouin zone center, we directly observe bimagnon which possess same energy scale as previously observed by Raman spectroscopy....
From small-angle neutron scattering studies of the flux line lattice (FLL) in CeCoIn5, with magnetic field applied parallel to crystal c-axis, we obtain field- and temperature-dependence FLL form factor, which is a measure spatial variation mixed state. We extend our earlier work [A.D. Bianchi et al. 2008 Science 319, 177] temperatures up 1250 mK. Over entire temperature range, paramagnetism cores results an increase factor field. Near H_c2 decreases again, indicate that this fall-off...
We use small-angle neutron scattering to study the superconducting vortex lattice in La${}_{2\ensuremath{-}x}$Sr${}_{x}$CuO${}_{4}$ as a function of doping and magnetic field. show that near optimally coordination coherence length $\ensuremath{\xi}$ are controlled by Van Hove singularity crossing Fermi level Brillouin zone boundary. The properties change dramatically spin-density-wave instability is approached upon underdoping. Bragg glass paradigm provides good description this regime...
We report on muon spin rotation studies of the noncentrosymmetric heavy fermion antiferromagnet CeRhSi3. A drastic and monotonic suppression internal fields, at lowest measured temperature, was observed upon an increase external pressure. Our data suggest that ordered moments are gradually quenched with increasing pressure, in a manner different from pressure dependence Néel temperature. At 23.6 kbar, magnetic fully suppressed via second-order phase transition, T(N) is zero. Thus, we...
Phase transitions and symmetry are intimately linked. Melting of ice, for example, restores translation invariance. The mysterious hidden order (HO) phase ${\mathrm{URu}}_{2}{\mathrm{Si}}_{2}$ has, despite relentless research efforts, kept its breaking element intangible. Here, we present a high-resolution x-ray diffraction study the crystal structure as function hydrostatic pressure. Below critical pressure threshold ${p}_{c}\ensuremath{\approx}3$ kbar, no tetragonal lattice is observed...
Ultrafast laser pulses can be used to drive materials into nonequilibrium states that have unusual properties and are promising for technological applications. Different classes of phenomena observed during after the optical illumination. This Colloquium discusses recent developments in this field, prospects using these techniques create with novel functionalities a controlled way.
We study the zero-point and thermal ionic motion in ${\text{La}}_{2}$${\text{CuO}}_{4}$ by means of high-resolution neutron-diffraction experiments. Our results demonstrate anisotropic O and, to a lesser extent, Cu ions, both consistent with structure coupled ${\text{CuO}}_{6}$ octahedra, quantify relative effects contributions motion. By substitution $^{18}\mathrm{O}$, we find that oxygen isotope effect on lattice dimensions is small negative ($\ensuremath{-}0.01%$), while displacement...
We present small angle neutron scattering studies of the vortex lattice (VL) in CeCoIn5 with magnetic fields applied parallel (H) to antinodal [100] and nodal [110] directions. For H is [100], a single VL orientation observed, while 90° reorientation transition found for [110]. both field orientations configurations we find distorted hexagonal an anisotropy, Γ=2.0±0.05. The form factor shows strong Pauli paramagnetic effects similar what have previously been reported [001]. At high fields,...