A5030990778- Nuclear physics research studies
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Physics of Superconductivity and Magnetism
- Semiconductor Quantum Structures and Devices
- Quantum Chromodynamics and Particle Interactions
- Astronomical and nuclear sciences
- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Physics Studies
- Particle physics theoretical and experimental studies
- 2D Materials and Applications
- Electronic and Structural Properties of Oxides
- Iron-based superconductors research
- X-ray Spectroscopy and Fluorescence Analysis
- Spectroscopy and Laser Applications
- Topological Materials and Phenomena
- Neutrino Physics Research
- Nuclear reactor physics and engineering
- Atomic and Subatomic Physics Research
- Chalcogenide Semiconductor Thin Films
- Advanced NMR Techniques and Applications
- High-Energy Particle Collisions Research
- Magnetic properties of thin films
- Semiconductor Lasers and Optical Devices
- Radiation Detection and Scintillator Technologies
The University of Tokyo
2013-2025
Saitama University
2010-2024
Helmholtz Institute Jena
2019
National Institute of Standards and Technology
2014-2018
University of Michigan
2016-2018
University of Colorado Boulder
2018
Canon (Japan)
2016
GSI Helmholtz Centre for Heavy Ion Research
2016
Waseda University
1988-2014
Tokyo Institute of Technology
1996-2013
A search for new isotopes using in-flight fission of a 345 MeV/nucleon 238 U beam has been carried out at the RI Beam Factory RIKEN Nishina Center. Fission fragments were analyzed and identified by superconducting separator BigRIPS. We observed 45 neutron-rich isotopes: 71 Mn, 73,74 Fe, 76 Co, 79 Ni, 81,82 Cu, 84,85 Zn, 87 Ga, 90 Ge, 95 Se, 98 Br, 101 Kr, 103 Rb, 106,107 Sr, 108,109 Y, 111,112 Zr, 114,115 Nb, 115,116,117 Mo, 119,120 Tc, 121,122,123,124 Ru, 123,124,125,126 Rh, 127,128 Pd, 133...
Abstract Photoexcitation is a very powerful way to instantaneously drive material into novel quantum state without any fabrication, and variable ultrafast techniques have been developed observe how electron, lattice, spin degrees of freedom change. One the most spectacular phenomena photoinduced superconductivity, it has suggested in cuprates that transition temperature T c can be enhanced from original with significant lattice modulations. Here, we show possibility for another high-...
Using light to manipulate materials into desired states is one of the goals in condensed matter physics, since control can provide ultrafast and environmentally-friendly photonics devices. However, it generally difficult realise a photo-induced phase which not merely higher entropy corresponding high-temperature at equilibrium. Here, we report realization insulator-to-metal transitions Ta2Ni(Se1-xSx)5 including excitonic insulator using time- angle-resolved photoemission spectroscopy. From...
A search for new isotopes using in-flight fission of a 345 MeV/nucleon 238 U beam has been carried out in the commissioning experiment next-generation radioactive isotope separator BigRIPS at RI Beam Factory RIKEN Nishina Center. Two neutron-rich palladium 125 Pd and 126 were observed first time, which demonstrates great potential factory.
We analyze recently-measured total reaction cross sections for 24-38Mg isotopes incident on 12C targets at 240 MeV/nucleon by using the folding model and antisymmetrized molecular dynamics(AMD). The well reproduces measured sections, when projectile densities are evaluated deformed Woods-Saxon (def-WS) with AMD deformation. Matter radii of then deduced from fine-tuning parameters def-WS model. matter largely enhanced nuclear Fully-microscopic calculations no free parameter reproduce 24-36Mg,...
Photoinduced phase transitions have been intensively studied owing to their promising potential for next-generation devices. Here, the authors develop a novel analysis method: so-called frequency-domain ARPES (FDARPES). They extend well established measurement method of time-domain detect how electrons are interacting with phonons during photoinduced insulator-to-metal transition Ta${}_{2}$NiSe${}_{5}$. successfully unravel underlying nature transition. This has general applicability other...
High-resolution spectroscopy of ${\ensuremath{\pi}}^{+}$ from ${K}^{\ensuremath{-}}$ absorption at rest has been used for the first time to identify ${\ensuremath{\Sigma}}^{\ensuremath{-}}$ hypernuclear states. The observed spectrum a ${(\mathrm{CH})}_{n}$ target revealed ${p}_{\frac{3}{2}}\ensuremath{-}{p}_{\frac{1}{2}}$ doublet $_{{\ensuremath{\Sigma}}^{\ensuremath{-}}}^{12}\mathrm{Be}$ with narrow widths. spin-orbit splitting is deduced be 5 MeV, 0.8 times that nucleons.
We investigated the formation dynamics of excitons and electron-hole (e-h) droplets (EHDs) in Si by using broadband terahertz time-domain spectroscopy. The indirect was studied observing their 1S-2P transition. Changes surface plasmon resonance EHDs showed a gradual condensation from homogeneous e-h plasma at densities above exciton-Mott Excitonic correlations were shown to exist prior EHD even Mott density.
The core-excited isomer in fully-ionized 133Sb has been directly studied for the first time by applying novel technique of isochronous mass spectrometry at GSI. neutron-rich nuclides high charge states were produced projectile fission 411 MeV A 238U ions, separated flight fragment separator (FRS) and stored storage ring (ESR). measured excitation energy is 4.56(10) MeV. neutral-atom half-life known to be 17 μs. This shortest-lived with techniques. extended in-flight bare ions ESR, which due...
Exciton Mott transition in Si is investigated by using terahertz time-domain spectroscopy. The excitonic correlation as manifested the 1s-2p resonance observed above density. scattering rate of charge carriers prominently enhanced at proximity density, which attributed to non-vanishing exciton metallic electron-hole plasma. Concomitantly, signature plasmon-exciton coupling loss function spectra.
The longitudinal momentum (P(axially)) distributions of one- and two-neutron removal fragments ((21,22)O) 23O from the reaction with a C target at 72 A MeV have been measured for first time using new direct time-of-flight method nearly full acceptance breakup fragments. unexpectedly narrow width 21O ( 115 +/- 34 MeV/c in FWHM) is consistent two neutrons occupying 2s(1/2) orbital 23O. This indicates modification core (22O) structure neutron halo-like sd shell nuclei near drip line. also...
The cross section for the $^{8}\mathrm{Li}$(\ensuremath{\alpha},n${)}^{11}$B reaction, which is crucial to predictions of primordial nucleosynthesis in inhomogeneous models, has been measured using radioactive-beam facility Institute Physical and Chemical Research (RIKEN). reaction all allowed $^{11}\mathrm{B}$ states was found be larger than that just ground state by about a factor 5.
Coherent control of a strongly inhomogeneously broadened system, namely, InAs self-assembled quantum dots, is demonstrated. To circumvent the deleterious effects inhomogeneous broadening, which usually masks results coherent manipulation, we use prepulse two-dimensional spectroscopy to provide size-selective readout ground, exciton, and biexciton states. The dependence on timing due dynamics coherently generated populations. further validate results, performed polarization dependent...
Ultrafast carrier dynamics in a graphene system are very important terms of optoelectronic devices. Recently, twisted bilayer has been discovered that possesses interesting electronic properties owing to strong modifications interlayer couplings. Thus, better understanding ultrafast is highly desired. Here, we reveal the unbalanced electron distributions quasicrystalline 30° (QCTBG), using time- and angle-resolved photoemission spectroscopy on femtosecond time scale. We distinguish...
The exciton coherent signal decay rate in GaAs quantum wells, as measured four-wave mixing experiments, depends on the polarization of excitation pulses. Using polarization-dependent two-dimensional spectroscopy, we show that this behavior is due to bosonic character excitons. Interference between two different mechanical pathways results a smaller for cocircular and colinear optical This interference does not exist cross-linearly polarized pulses resulting larger rate. Our result shows...
X-ray-induced carrier dynamics in silicon and gallium arsenide were investigated through intensity variations of transmitted terahertz (THz) pulses the pico- to microsecond timescale with x-ray free-electron laser synchrotron radiation. We observed a steep reduction THz transmission picosecond scale due x-ray-induced generation, followed by recovery on nano- caused recombination carriers. The rapid response former process is applicable direct determination temporal overlap between for...
Inhomogeneous broadening in ensembles of semiconductor quantum dots (QDs) has hindered coherent operations due to the detuning effects, caused by large fluctuation QD transition energy size dispersion. This difficulty is especially evident when using femtosecond laser pulses for excitation. Here, authors successfully measure detuning-dependent evolution a ensemble employing prepulse two-dimensional spectroscopy. The dephasing mechanism found be significantly different from that observed...
Temporal and latitudinal variations of vertical profiles N 2 O isotopomers were observed in the stratosphere over Japan (39°N, 142°E), Sweden (68°N, 20°E), Antarctica (69°N, 40°E) during period between 1990 2001. Samples collected with a balloon‐borne cryogenic sampler analyzed by mass spectrometry laboratory. Observed enrichment factors for heavier ( 15 14 16 O, 18 O) relative to nearly constant lower (less than ∼22 km) but increased at higher altitudes (∼22–35 while showing seasonal...