A5033344883- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Particle physics theoretical and experimental studies
- Iron-based superconductors research
- Electron and X-Ray Spectroscopy Techniques
- Quantum Chromodynamics and Particle Interactions
- Advanced Chemical Physics Studies
- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Surface and Thin Film Phenomena
- Crystal Structures and Properties
- Magnetic properties of thin films
- High-Energy Particle Collisions Research
- Spectroscopy and Quantum Chemical Studies
- Inorganic Chemistry and Materials
- Acoustic Wave Resonator Technologies
- Rare-earth and actinide compounds
- Quantum and electron transport phenomena
- Crystallography and molecular interactions
- Ion-surface interactions and analysis
- Laser-Matter Interactions and Applications
- Semiconductor materials and devices
- Advanced Materials Characterization Techniques
- Physics of Superconductivity and Magnetism
- Electronic and Structural Properties of Oxides
Hitachi (Japan)
2001-2017
Nagasaki University
2015-2017
The University of Tokyo
1987-2016
Toho University
2001-2014
Hitachi (United Kingdom)
2002-2010
Rissho University
2000-2005
Tokyo Metropolitan University
2005
University of Pittsburgh
2002
Cornell University
1997-1999
National Institute for Agro-Environmental Sciences
1999
The fine particulate matter (PM2.5) problem has attracted much scientific and public attention, due to its effects on visibility, human health, global climate. There are three factors that have important effect PM2.5 mass concentration: domestic pollutant emission sources, external sources outside of the country, meteorological conditions. Nagasaki is a coastal prefecture located at westernmost part Japan, which an ideal location study pollutants from long range transport correlation between...
The dynamics of cesium atom motion above the copper(111) surface following electronic excitation with light was studied femtosecond (10(-15) seconds) time resolution. Unusual changes in structure within 160 femtoseconds after excitation, observed by time-resolved two-photon photoemission spectroscopy, are attributed to atomic a copper-cesium bond-breaking process. Describing change energy antibonding state simple classical model provides information on mechanical forces acting atoms that...
Lifetimes of hot electrons in the 1.3--3.2-eV energy range at low index surfaces Cu((100),(110),(111)) are measured by two-photon time-resolved photoemission spectroscopy with 10 fs resolution. Energy dependence lifetimes deviates from (E-${\mathrm{E}}_{\mathrm{F}}$${)}^{\mathrm{\ensuremath{-}}2}$ functional form predicted standard Fermi-liquid theory for free-electron metals, but a qualitative agreement is obtained calculating e-e scattering times band structure Cu. However, magnitude...
The polarization dynamics induced by the optical excitation of s,p-band derived occupied surface state on Cu(111) are studied a new technique, interferometric two-photon time-resolved photoemission. decay due to phase breaking collisions charge carriers an $\ensuremath{\sim}20\mathrm{fs}$ time scale is modeled Bloch equations. resolution also allows direct observation nonlinear oscillations at harmonics frequency, which lead harmonic generation.
Electron dynamics induced by direct photoexcitation of the antibonding state on Cs/Cu(111) surface are studied interferometric time-resolved two-photon photoemission. Femtosecond resolution pump-probe correlation measurements indicate phase and energy decay, respectively, 15 50 fs time scales for Cs at 33 K. Both polarization nonexponential strongly temperature dependent. The dependence population is consistent with photodesorption.
Preferential flow is ubiquitous in field soils, where it has important practical implications for water and contaminant transport. Dyes are frequently used to visualize preferential pathways. The fact that stain patterns pictures of soil profiles often exhibit convoluted geometries, reminiscent fractals, encouraged a number authors use the principles fractal geometry describe patterns. This description typically involves two numbers, mass surface dimension. evaluation either one via image...
The control of electron distribution excited in a metal through optical phase the excitation light is demonstrated. Two-photon photoemission from Cu(111) surface either by pair $\ensuremath{\sim}15\mathrm{fs}$ laser pulses with mutual delay fixed to an accuracy $\ifmmode\pm\else\textpm\fi{}0.025\mathrm{fs}$, or single, frequency-chirped pulse. As consequence coherence two-photon process, spectra do not only depend on frequency, as conventional spectroscopy, but also light. This may be...
We report measurements of current-induced magnetic torques in structures containing a $\ensuremath{\sim}1$-nm-thick layer an antiferromagnet IrMn. perform ac-electrical Ta/IrMn/CoFeB and Ta/IrMn below above the N\'eel temperature ultrathin IrMn compare results with control experiments Ta/CoFeB bilayer. employ second harmonics technique to detect effects symmetry analysis that enables us separate distinct contributions signal. identify signals generated by thermal gradient sample originating...
Abstract The recent development of spin dynamics opens perspectives for various applications based on waves, including logic devices. first important step in the realization spin-wave-based logics is manipulation spin-wave interference. Here, we present experimental a micrometre-scale interferometer consisting two parallel waveguides. waves propagate through waveguides and superposition or interference electrical signals corresponding to measured. A direct current flowing metal wire...
This review presents a case study of the direct, real-time observation surface photochemical reaction, namely frustrated photodesorption alkali atoms from noble metal surfaces. Charge transfer excitation an electron substrate into unoccupied resonance atom instantaneously turns on repulsive Coulomb force inducing nuclear motion both adsorbate and atoms. The incipient wave packet dynamics are documented for Cs/Cu(111) through accompanying change in electronic structure. intimate view...
$d$-band hole decoherence times in copper are measured with energy and momentum resolution for the Cs/Cu(100) surface at 33--300 K by interferometric time-resolved two-photon photoemission technique. At top of $d$ bands ( ${X}_{5}$ point) 33 time ${T}_{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}34.5\ifmmode\pm\else\textpm\fi{}1.5\mathrm{fs}$ has contributions from population decay due to Auger recombination...
The electronic excitation of chemisorbed Cs atoms through the coherent photoinduced charge transfer from Cu(111) surface turns on repulsive forces that initiate dissociative wave packet motion. Due to unusually slow relaxation, with interferometric time-resolved two-photon photoemission technique it is possible follow characteristic change in structure due ensuing nuclear dynamics for ∼200 fs after excitation. This direct observation incipient bond breaking process a metal provides...
The photoemission spectra of NiS in both antiferromagnetic and Pauli paramagnetic phases show similar characteristic features localized d electrons. This finding is contrast with the results band-structure calculations which predict drastic spectral changes between two phases. It suggested that fluctuations Ni 3d local moments due to hybridization S 3p states near Fermi level are responsible for behavior.
We report the first observation of a b -> u type charmless baryonic B decay, B+ p pbar pi+, as well s B0 K0 and K*+ decays. The analysis is based on 78fb^{-1} data sample recorded Upsilon(4S) resonance with Belle detector at KEKB. find BF(B+ pi+) = (3.06^{+0.73}_{-0.62} \pm 0.37)*10^{-6}, BF(B0 K0) =(1.88^{+0.77}_{-0.60} 0.23)*10^{-6}, K*+) (10.3^{+3.6 + 1.3}_{-2.8 -1.7})*10^{-6}. also update K+) (5.66^{+0.67}_{-0.57} 0.62)* 10^{-6}, present an upper limit K*0) 90% confidence level. A common...
We report the first observation of charmless hyperonic B decay, B0-->pLambda(pi)(-), using a 78 fb(-1) data sample recorded on Upsilon(4S) resonance with Belle detector at KEKB. The measured branching fraction is B(B0-->pLambda(pi)(-))=(3.97(+1.00)(-0.80)+/-0.56)x10(-6). Searches for B0-->pLambda(K)- and pSigma(0)pi(-) yield no significant signals we set 90% confidence-level upper limits B(B0-->pLambda(K)-)<8.2x10(-7) B(B0-->pSigma(0)pi(-))<3.8x10(-6).
Abstract Recent progress in magnetic tunnel junctions (MTJs) with a perpendicular easy axis consisting of CoFeB and MgO stacking structures has shown that magnetization dynamics are induced due to voltage-controlled anisotropy (VCMA), which will potentially lead future low-power-consumption information technology. For manipulating magnetizations MTJs by applying voltage, it is necessary understand the coupled motion two (recording reference) layers. In this report, we focus on layers top an...
Photoemission and inverse photoemission measurements are reported for icosahedral crystalline phases of Al-Li-Cu with similar compositions. In the spectra, Al Li core states quasicrystal shifted to larger binding energies from those phase by 0.4 eV, in contrast negligible shift Cu states. A gaplike feature density is observed spectra just above Fermi level. Comparison between theoretical calculation experimental results discussed.
In this work, we investigated a scalability of spin accumulation signal for various device sizes. We found that the is enhanced by shrinking Cu wire width and thickness. Moreover estimate to noise ratio (SNR) head structure using size dependence signal. The SNR increases with reducing nonmagnetic thickness, which are corresponding track gap width, respectively. And it has maximum value around 2 ~ 3 Tbit/inch <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Ultrafast (femtosecond) interferometric pump–probe techniques can be used to measure rates of population and quantum phase decay in complicated media such as liquids solids. However, the levels probed systems are often inhomogeneously broadened or part a continuum states. The use broadband ultrafast lasers thus results multiple being excited detected. inherent averaging that is due this effect alter measured coherent response, affecting information retrieved on decay. importance these...
Electron lifetimes in a high- ${T}_{c}$ cuprate ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8+\ensuremath{\delta}}$ are measured directly time domain by the interferometric two-photon time-resolved photoemission technique. The decrease from 60 to 10 fs an energy range of 1.4 3.0 eV above ${E}_{F}$ with approximately $({E\ensuremath{-}E}_{F}{)}^{\ensuremath{-}2}$ scaling normal, Fermi liquid metal. However, anomalous behavior shows up pronounced temperature dependence...
X-ray and vacuum ultraviolet photoemission spectra were measured for valence fluctuating Yb 4 X 3 (X: As, Sb Bi) by use of Mg K α synchrotron radiation source. From the line shape analysis f spectra, mean is evaluated as 2.32, 2.34 2.10 As ,Yb Bi . The surface level shift estimated 0.65, 0.63 0.59 eV, respectively. plasmon satellite confirmed in d core XPS contrast to those YbAs. anionic states, 5 UPS spectrum showed a remarkable asymmetry rather symmetric spectrum. This result suggests...