A5010822202- Muon and positron interactions and applications
- Semiconductor materials and devices
- Advanced Condensed Matter Physics
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Advancements in Battery Materials
- Graphene research and applications
- Ion-surface interactions and analysis
- Atomic and Molecular Physics
- Fuel Cells and Related Materials
- Integrated Circuits and Semiconductor Failure Analysis
- Physics of Superconductivity and Magnetism
- Solid-state spectroscopy and crystallography
- Ammonia Synthesis and Nitrogen Reduction
- Magnetic and transport properties of perovskites and related materials
- Marine animal studies overview
- Silicon and Solar Cell Technologies
- Conducting polymers and applications
- Topological Materials and Phenomena
- Advanced NMR Techniques and Applications
- Chalcogenide Semiconductor Thin Films
- Particle physics theoretical and experimental studies
- 2D Materials and Applications
- Rare-earth and actinide compounds
- solar cell performance optimization
China Spallation Neutron Source
2025
ISIS Neutron and Muon Source
2024-2025
Rutherford Appleton Laboratory
2013-2024
Science and Technology Facilities Council
2021-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste
2024
Queen Mary University of London
2013-2021
Research Complex at Harwell
2021
Chilton Medical Center
2019
Cubic (United States)
2012-2016
RIKEN Nishina Center
2011-2014
We report the discovery of a novel gapless quantum spin liquid in S=1 honeycomb system Cu3LiRu2O6 with Ru4+ (4d4) where moments remain dynamic down to 50 mK. Heat capacity measurements show no sign magnetic ordering 60 mK spite Curie-Weiss temperature = -222 K indicating strong antiferromagnetic interaction. In zero field, heat shows linear T-dependence Sommerfeld coefficient 107 mJ/mol K2 is much larger than that found typical Fermi liquids. Our local probe 7Li nuclear resonance (NMR) find...
Emission of muonium (|$\mu ^+e^-$|) atoms from a laser-processed aerogel surface into vacuum was studied for the first time. Laser ablation used to create hole-like regions with diameter about 270 |$\mu $|m in triangular pattern hole separation range 300–500 $|m. The emission probability sample is at least eight times higher than uniform one.
FAMU is an INFN-led muonic atom physics experiment based at the RIKEN-RAL muon facility ISIS Neutron and Muon Source (United Kingdom). The aim of to measure hyperfine splitting in hydrogen determine value proton Zemach radius with accuracy better than 1%. has a scintillating-fibre hodoscope for beam monitoring data normalisation. In order carry out flux estimation, low-rate measurements were performed extract single-muon average deposited charge. Then, detector simulation Geant4 FLUKA...
Sodium ion batteries are a promising alternative to current lithium battery technology, providing relatively high capacity and good cycling stability at low cost.
Abstract The FAMU experiment at RIKEN-RAL is a muonic atom with the aim to determine Zemach radius of proton by measuring 1s hyperfine splitting in hydrogen. activity Collaboration years 2015–2023 enabled final optimisation detector-target setup as well gas working condition terms temperature, pressure and mixture composition. has started its data taking July 2023. status detector for 2023 experimental runs, beam characterisation X-ray detection 100–200 keV energy range, presented discussed.
As one of the principal muon beam line at J-PARC facility (MUSE), we are now constructing a Muon (U-Line), which consists large acceptance solenoid made mineral insulation cables (MIC), superconducting curved transport and axial focusing magnets. There, can extract 2 × 108/s surface muons towards hot tungsten target. At U-Line, establishing new type microscopy; technique with use intense ultra-slow source generated by resonant ionization thermal Muonium (designated as Mu; consisting μ + an e...
Recently, there have been contrary claims of Kitaev spin-liquid behavior and ordered in the honeycomb compound ${\mathrm{Ag}}_{3}\mathrm{Li}{\mathrm{Ir}}_{2}{\mathrm{O}}_{6}$ based on various experimental signatures. Our investigations this system reveal a low-temperature state with persistent dynamics down to lowest temperatures. Magnetic order is confirmed by clear oscillations muon spin relaxation ($\ensuremath{\mu}\mathrm{SR}$) time spectrum below 9 K until 52 mK. Coincidentally...
The relationship between electric displacement D and field E was studied for polyamides consisting of m -xylylenediamine aliphatic dicarboxylic acids with numbers carbon atoms from 6 to 11 13. Regardless the number in acids, quenched samples these exhibit a D-E hysteresis loop remanent polarization 23-67 mC·m -2 . Polarization is related amide groups aligned by field.
A laser-pump, positron-probe technique has been developed for measuring the dynamics of laser-induced paramagnetic centers in porous materials. The basis is fact that annihilation rate ortho-positronium may increase presence unpaired spins. By using an intense positron pulse to create positronium atoms a silica sample we have used this effect as probe measure time dependence recombination centers. We observed nonexponential postirradiation decay kinetics extending over ten orders magnitude...
We have measured excess carrier lifetime in silicon using photoexcited muon spin spectroscopy. Positive muons implanted deep a wafer can interact with the optically injected carriers and directly probe bulk while minimizing effect from surface recombination. The method is based on relaxation rate of asymmetry, which depends density. underlying microscopic mechanism has been understood by simulating four-state muonium model Si under illumination. apply technique to different injection levels...
Sodium transition metal oxides with a layered structure are one of the most widely studied cathode materials for Na+-ion batteries. Since mobility Na+ in such is key factor that governs performance material, electrochemical and muon spin rotation relaxation techniques here used to reveal P2-type Na0.5MgxNi0.17-xMn0.83O2 (x = 0, 0.02, 0.05 0.07) material. Combining as galvanostatic cycling, cyclic voltammetry, intermittent titration technique μ+SR, we have successfully extracted both...
Abstract The iron-pnictide superconductors have generated tremendous excitement as the competition between magnetism and superconductivity has allowed unique in-roads towards elucidating a microscopic theory of unconventional high-temperature superconductivity. In addition to stripe spin density wave ( $${C}_{2M}^{a}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mrow> <mml:mi>C</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> <mml:mi>M</mml:mi> <mml:mi>a</mml:mi>...
Photoexcited muon spin spectroscopy (photo-μSR) is used to study excess charge carrier lifetimes in silicon. Experiments are performed on silicon wafers with very high bulk the surface passivation conditions intentionally modified control effective lifetime. When lifetime low (&lt;500 μs), implanting muons different depths enables reliable measurement of as a function distance from surface. It also demonstrated that photo-μSR technique can measure completed commercial gallium doped...
We discuss the general principles of laser-excited muon pump–probe spin spectroscopy (photo-μSR), including historical origins technique, and overall experimental method. review examples past work using this then future upgrade HiFi spectrometer with a high-power laser system. In particular, we note that performing photo-μSR experiments at high field around avoided level crossing resonances in unsaturated organic materials, offers advantages over previously performed lower magnetic fields....
Emission of muonium ($\mu^{+}e^{-}$) atoms from silica aerogel into vacuum was observed. Characteristics emission were established samples with densities in the range 29 mg cm$^{-3}$ to 178 cm$^{-3}$. Spectra decay times correlated distances surfaces, which are sensitive speed distributions, follow general features expected a diffusion process, while small deviations simple room-temperature thermal model identified. The parameters process deduced observed yields.
In the present work, we demonstrate that C-doped Zr5Pt3is an electron-phonon superconductor (with critical temperatureTC= 3.8 K) with a nonsymmorphic topological Dirac nodal-line semimetal state, which report here for first time. The superconducting properties of Zr5Pt3C0.5have been investigated by means magnetization, resistivity, specific heat, and muon spin rotation relaxation (μSR) measurements. We find at low temperatures, depolarization rate is almost constant it can be well described...
The article gives the motivations for measurement of hyperfine splitting (hfs) in ground state muonic hydrogen to explore properties proton at low momentum transfer. It summarizes these proposed methods and finally describes FAMU experiment more detail.
We present the analysis of gas transport in micro porous layers polymer electrolyte fuel cells based on three-dimensional structure data obtained from X-ray nano computed tomography (CT). The characteristic pore size is comparable to mean free path molecules. polygonal surface representation constructed volumetric CT image using marching tetrahedrons algorithm. diffusion fluxes molecules through layer are evaluated by direct simulation Monte Carlo method, which can reproduce transition...
We report current constructing states of the Ultra Slow Muon Beam at U-line / MUSE J-PARC, which are supported by thermal muonium (Mu, μ+e−) production with most intense pulsed slow muon beam, laser resonant ionization, and transportation Beam. A Mu is produced a hot tungsten foil in Mu-production chamber. At ionization process, ionized coherent vacuum ultraviolet radiation 355-nm radiation. The sources developed RIKEN, installed cabin, connected via VUV steering chamber
A high power pulsed laser system has been installed on the magnetic field muon spectrometer (HiFi) at ISIS neutron and source, situated STFC Rutherford Appleton Laboratory in UK. The upgrade enables one to perform light-pump muon-probe experiments under a field, which opens new applications of spin spectroscopy. In this report we give an overview principle HiFi Laser system, describe newly developed techniques devices that enable precisely controlled photoexcitation samples instrument....
In our ZF μ+ SR studies of the spin-dependent response to polarized conduction electrons produced by circularly 830 nm laser light in a semi-metallic and strain-free n-type GaAs (3×1016 cm-3 Si), among possible states positive muon, Mu− (μ+e−e−) had been found take exchange scattering, while muonium (Mu0) at bond-center was be insensitive. order understand this surprising response, LF (up 0.4 T) μ+SR were carried out data is suggesting contribution bound electron(s) Mu−. Possible mechanisms...
We present a theoretical model combined with computational study of laser four-wave mixing process under optical discharge in which the non-steady-state amplitude equations are integrated kinetic initial and electron avalanche ionization Kr-Ar gas. The is validated by earlier experimental data showing strong inhibition generation pulsed, tunable Lyman-\ensuremath{\alpha} (Ly-\ensuremath{\alpha}) radiation when using sum-difference frequency 212.6 nm infrared (820--850 nm). rigorous approach...
We investigated the influence of near-surface defects induced by reactive ion etching on electrical properties Pt/n-Si interface. By analyzing temperature dependence I-V characteristics damaged interface, we confirmed that dominant current transport in interface was thermionic emission process under our experimental conditions. The Schottky barrier height lowered due to change Fermi-level position at positively charged donor-like are responsible for