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Sheng, L.*; 山本 慧; 他18名*
Nature Physics, 8 Pages, 2025/04
被引用回数：1Controlling the spin current lies at the heart of spintronics and its applications. In ferromagnets, the sign of spin currents is fixed once the current direction is determined. However, spin currents in antiferromagnets can possess opposite polarizations, but this requires enormous magnetic fields to lift the degeneracy between the two modes. Therefore, controlling spin currents with opposite polarization is still a challenge. Here we demonstrate the control of spin currents at room temperature by magnon interference in a canted antiferromagnet, namely, haematite that has recently been classified as an altermagnet. Magneto-optical characterization by Brillouin light scattering reveals that the spatial periodicity of the beating patterns is tunable via the microwave frequency. We further observe that the inverse spin Hall voltage changes sign as the frequency is tuned, evincing a frequency-controlled switching of polarization of pure spin currents. Our work highlights the use of antiferromagnetic magnon interference to control spin currents, which substantially extends the horizon for the emerging field of coherent antiferromagnetic spintronics.
Lim, G.-C.*; 福谷 克之; 他8名*
Journal of the American Chemical Society, 146(46), p.32013 - 32021, 2024/11
被引用回数：3 パーセンタイル：57.75(Chemistry, Multidisciplinary)We investigate ultrahigh concentration doping of hydrogen (H) into rutile-TiO(100) single crystals by low-energy (2.5 keV) hydrogen ion beam irradiation at low temperature (LT). While the hydrogen concentration was limited to H
TiO at 300 K, in situ nuclear reaction analysis (NRA) revealed ultrahigh concentration doping of hydrogen up to H
TiO by the LT irradiation at 50 K. The large (
8.2%) expansion of the out-of-plane lattice constant suggests that hydrogen occupies interstitial sites in rutile TiO. Hydrogens of early stage irradiation act as electron donors and induce a large increase in conductivity, which is consistent with theoretical studies in the dilute limit. The nature of excess H was investigated in situ by transport and photoemission measurements. After LT excess H doping and postannealing to room temperature, unusual electrical transport properties were observed while maintaining the ultrahigh H concentration. In situ photoemission measurements show that the excessively doped hydrogens by LT irradiation generate a deeper in-gap state (IGS) of metastable nature. Density functional theory predicts the formation of double neighboring interstitial hydrogens as a possible mechanism for the deeper IGS.
Cf fission fragments with MRTOF-MS and detailed study of masses of neutron-rich Ce isotopes木村 創大*; 伊藤 由太; 他8名*
Physical Review C, 110(4), p.045810_1 - 045810_9, 2024/10
被引用回数：2 パーセンタイル：58.81(Physics, Nuclear)We report the mass measurements of neutron-rich isotopes produced via spontaneous fission of Cf using a multireflection time-of-flight mass spectrograph. The mass of 
Ce is determined experimentally for the first time. A discrepancy between the experimental and literature values was found for the mass of 
Sb, which was previously deduced through indirect measurements. In comparison with several theoretical predictions, both the values and the trend of the mass excesses of 
Ce cannot be consistently explained. The wide-range and simultaneous mass measurements of the multireflection time-of-flight mass spectrograph enable us to crosscheck the existing mass data, and the conflict between the measured time-of-flight ratio and the extracted mass would imply the necessity of re-examining them.
Tl; Shape coexistenceGuo, C. Y.*; Andreyev, A. N.; 他38名*
European Physical Journal A, 60(8), p.165_1 - 165_10, 2024/08
被引用回数：0 パーセンタイル：0.00(Physics, Nuclear)The prompt and delayed 
-ray spectra of Tl was studied via the 
Nd(
Cr, 
)Tl fusion-evaporation reaction. The collective bands with one-quasiparticle configurations from the 2
, 1
, 1
, and 1
orbitals and high-lying structures with possible three-quasiparticle configurations are investigated in terms of the tilted axis cranking covariant density functional theory. At low excitation energy, the rotational bands with one-quasiparticle configurations reflect coexistence of three shapes: prolate, triaxial, and oblate. The possible shapes of two microsecond isomers at high excitation energy are proposed.
Li, P. J.*; 宇都野 穣; 吉田 数貴; 他85名*
Physics Letters B, 855, p.138828_1 - 138828_11, 2024/08
被引用回数：2 パーセンタイル：58.81(Astronomy & Astrophysics)We report on the first measurement of unbound states in 
Ca and 
Ca, populated from 
Ca
reactions. Orbital angular momentum 
assignments were extracted from momentum distributions calculated with the distorted wave impulse approximation (DWIA). The resonances at 5516(41) keV in Ca and 6000(250) keV in Ca indicate a significant = 3 component, providing the first experimental evidence for the 
single-particle strength of unbound hole states in the neutron-rich Ca isotopes. The observed excitation energies and cross-sections point towards extremely localized and well separated strength distributions, with some fragmentation for the orbital in Ca. These results are in good agreement with predictions from shell-model calculations using the effective GXPF1Bs interaction and ab initio calculations and diverge markedly from the experimental distributions in the nickel isotones at Z = 28.
船引 雄太*; 伊與田 宗慶*; 菖蒲 敬久; 松田 朋己*; 林 雄二郎*; 佐野 智一*; 他8名*
Journal of Manufacturing Processes, 115, p.40 - 55, 2024/04
被引用回数：4 パーセンタイル：74.69(Engineering, Manufacturing)In resistance spot welding (RSW) of Fe and Al alloy, an intermetallic compound (IMC) is formed at the joining interface, and it is known that the joining strength of the joint decreases as the IMC becomes thicker. In this study, the convection behavior in the Al alloy melting zone of an Fe-Al alloy RSW was varied and the effect on the joint characteristics was investigated. For this study, focusing on the electromagnetic force generated in the Al alloy melting zone, the convection behavior in the Al alloy melting zone was changed by adding an external magnetic field using neodymium magnets. In-situ evaluation of the convection behavior using synchrotron radiation and cross-sectional macro-observation of the joint revealed that the addition of an external magnetic field causes a non-axisymmetric change in the convection behavior in the Al alloy melting zone, which results in the deflection of the Al alloy melting zone. The addition of an external magnetic field increases the driving force of convection and homogenizes the temperature field at the joining interface, suggesting that the IMC near the center is formed thin and uniform. Furthermore, from the cross tension test and the observation of the fracture surface of the joint after the test, it was clarified that the CTS of the joint with an external magnetic field was improved by the propagation of cracks into the Al alloy melting zone during the test.
Zhang, X.*; Gong, W.; 他8名*
International Journal of Plasticity, 173, p.103896_1 - 103896_24, 2024/02
被引用回数：20 パーセンタイル：98.96(Engineering, Mechanical)The distribution and partitioning of solute atoms in age-hardenable aluminum (Al) alloys markedly impact strength, ductility and failure of alloy materials, thus rendering the understanding of dislocation-obstacle (solute-rich features) interactions crucial in the development of a new class of heat-treatable Al alloys. Here, we investigate the slip mechanisms, strain localization and strain hardening of a high Mg-content lightweight AlMgZn-based crossover alloy aged to different conditions with the focus on the dislocation-obstacle interactions. It is found that due to different elemental partitioning between matrix and solute-rich features the interaction of dislocations with obstacles can be drastically different for samples with varying precipitates. The dislocations in the under-aged and near peak-aged samples show predominantly planar slip, which produces strain localization. Whereas in the over-aged sample, gliding dislocations initially bend between adjacent precipitates lying in the slip planes, and subsequently surmount them by local cross slip processes, giving rise to homogeneous slip. It is discovered that strain localization in the form of coarse slip bands induces strain hardening in the under-aged material. To understand the enhanced strain hardening observed in the under-aged sample, four key influencing factors are proposed. In addition, the predicted yield strengths for the solution-treated and artificially aged materials match well with those experimentally measured values.
Mao, W.*; 福谷 克之; 他8名*
International Journal of Hydrogen Energy, 50(Part D), p.969 - 978, 2024/01
被引用回数：5 パーセンタイル：33.95(Chemistry, Physical)Cerium oxide (CeO) is well known to be reducible by hydrogen (H), yet the diffusion and solution properties of hydrogen in ceria at elevated temperatures have remained challenging to evaluate. We therefore fabricated nanometer-thin (100 nm) cerium oxide films on Si(111) substrates by pulsed laser deposition (PLD) and quantitatively investigated the H depth distributions therein by means of resonant 
H(
N,
)
C nuclear reaction analysis (NRA) before and after annealing in H gas at 773-973 K. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS) reveal that the as-deposited films exhibit single phase CeO structure and partially reduced stoichiometry (CeO
). H annealing does not largely change the H content of the as-deposited films; in all conditions several atomic percent of hydroxyl (OH) are found to exist in a thin (4 nm) surface layer, whereas stably bound hydrogen in the bulk of the films is almost uniformly distributed and of much smaller quantity (0.2 at.%) than the oxygen vacancy concentration in the partially reduced ceria. Its low concentration and high thermal stability identify this bulk H species as likely being strongly bound to defects in the polycrystalline films rather than as a hydride species that interacts weakly with O-vacancies. The H diffusion coefficient and activation energy in the ceria films are determined as 
10
m
s
at 773-973 K and 
1.69 eV, respectively. The observed diffusion activation energy is somewhat larger than theoretical predictions for thermal diffusion of H in stoichiometric bulk CeO, suggesting that defects and oxygen vacancies in the PLD-fabricated ceria thin films possibly have an impact on the H mobility.
S-nuclear magnetic resonance measurements吉田 章吾*; 芳賀 芳範; 藤井 拓斗*; 中井 祐介*; 水戸 毅*; 他8名*
Journal of the Physical Society of Japan, 93(1), p.013702_1 - 013702_5, 2024/01
被引用回数：0 パーセンタイル：0.00(Physics, Multidisciplinary)In Kondo insulators, a small energy gap evolves only at low temperatures. In this study, S-nuclear magnetic resonance measurements under high pressures are performed to clarify the electronic structure of SmS. The spin-lattice relaxation time, consisting of multiple components, was analyzed based on a periodic Anderson model with Bayesian inference, leading to a peculiar small gap state arising from strong hybridization.
-II neutrino targetShin, C. D.*; 百々 拓; 羽賀 勝洋; 原田 正英; 長谷川 勝一; 春日井 好己; 木下 秀孝; 増田 志歩; 明午 伸一郎; 酒井 健二; et al.
Journal of Instrumentation (Internet), 18(12), p.T12001_1 - T12001_9, 2023/12
被引用回数：0 パーセンタイル：0.00(Instruments & Instrumentation)The JSNS (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment designed for the search for sterile neutrinos. The experiment is currently at the stage of the second phase named JSNS-II with two detectors at near and far locations from the neutrino source. One of the key components of the experiment is an acrylic vessel, that is used for the target volume for the detection of the anti-neutrinos. The specifications, design, and measured properties of the acrylic vessel are described.
Martel, I.*; Acosta, L.*; Aguado, J. L.*; Smallcombe, J.; 他68名*
Nuclear Instruments and Methods in Physics Research B, 541, p.176 - 179, 2023/08
被引用回数：3 パーセンタイル：46.61(Instruments & Instrumentation)The ISOLDE Scientific Infrastructure at CERN offers a unique range of post-accelerated radioactive beams. The scientific program can be improved with the Isolde Superconducting Recoil Separator (ISRS), an innovative spectrometer able to deliver unprecedented (A, Z) resolution. In this paper we present an overview of the physics and ongoing technical developments.
Se(n,) cross section up to 200 keV at the n_TOF facility at CERNSosnin, N. V.*; 原田 秀郎; 木村 敦; 他128名*
Physical Review C, 107(6), p.065805_1 - 065805_9, 2023/06
被引用回数：1 パーセンタイル：0.00(Physics, Nuclear)The Se(n,) reaction is of importance for Se abundance during the slow neutron capture process in massive stars. We have performed a new measurement of the Se radiative neutron capture cross section at the Neutron Time-of-Flight facility at CERN. Resonance capture kernels were derived up to 51 keV and cross sections up to 200 keV. Maxwellian-averaged cross sections were calculated for stellar temperatures between kT = 5 keV and kT = 100 keV, with uncertainties between 4.2% and 5.7%. Our results lead to substantial decreases of 14% and 19% in Se abundances produced through the slow neutron capture process in selected stellar models, compared to using previous recommendation of the cross section.
U and systematic high-precision atomic mass measurements of neutron-rich Pa-Pu nuclei produced via multinucleon transfer reactions庭瀬 暁隆*; 伊藤 由太; 他18名*
Physical Review Letters, 130(13), p.132502_1 - 132502_6, 2023/03
被引用回数：38 パーセンタイル：98.23(Physics, Multidisciplinary)新同位体Uを合成し、KISS施設の
U+
Pt系の多核子移行反応において、19種類の中性子過剰Pa-Pu同位体の系統的原子量測定が行われた。本実験結果は、この領域の核種において、
シェルギャップに向かう未踏の中性子過剰アクチニド同位体へのアクセスに多核子移行反応が重要な役割を果たすことを実証した。
production ratio in 
collisions at the 
resonance using 
decays at BelleChoudhury, S.*; 谷田 聖; Belle Collaboration*; 他198名*
Physical Review D, 107(3), p.L031102_1 - L031102_6, 2023/02
被引用回数：8 パーセンタイル：74.17(Astronomy & Astrophysics)We measure the ratio of branching fractions for the 
decays to 
and 
using 
and 
samples, where 
stands for 
(
or 
), with 
fb of data collected at the resonance with the Belle detector. We find the decay rate ratio of 
over 
to be 
, which is the most precise measurement to date. The first and second uncertainties are statistical and systematic, respectively, and the third uncertainty is systematic due to the assumption of isospin symmetry in 
.
and 
Li, Y.*; 谷田 聖; Belle Collaboration*; 他187名*
Physical Review D, 107(3), p.032001_1 - 032001_11, 2023/02
被引用回数：2 パーセンタイル：16.70(Astronomy & Astrophysics)We present the first search for the weak radiative decays and using a data sample of 980~fb collected by the Belle detector operating at the KEKB asymmetric-energy collider. There are no evident or signals. Taking the decays 
and 
as normalization channels, the upper limits at 90% credibility level on the ratios of branching fractions 
and 
are determined. We obtain the upper limits at 90% credibility level on the absolute branching fractions 
and 
.
and 
and tests of QCD factorizationKrohn, J.-F.*; 谷田 聖; Belle Collaboration*; 他198名*
Physical Review D, 107(1), p.012003_1 - 012003_12, 2023/01
被引用回数：1 パーセンタイル：16.70(Astronomy & Astrophysics)Using 
meson pairs recorded by the Belle experiment at the KEKB 
collider, we report the branching fractions 
and 
; the quoted uncertainties are statistical and systematic, respectively. A measurement of the ratio of these branching fractions is also presented, 
, where systematic uncertainties due to the 
meson reconstruction cancel out. Furthermore, we report a new QCD factorization test based on the measured ratios for 
and 
decays at squared momentum transfer values equivalent to the mass of the 
or 
hadron. The parameters 
are measured to be 
and 
, where the last uncertainties account for all external inputs. These values are approximately 
lower than those expected from theoretical predictions. Subsequently, flavor 
symmetry is tested by measuring the ratios for pions and kaons, 
, as well as for different particle species. The ratio is consistent with unity and therefore no evidence for symmetry breaking effects is found at the 
precision level.
Ge(n,) cross section below 70 keV measured at n_TOF CERNLederer-Woods, C.*; 原田 秀郎; 木村 敦; 他128名*
European Physical Journal A, 58(12), p.239_1 - 239_9, 2022/12
被引用回数：0 パーセンタイル：0.00(Physics, Nuclear)Neutron capture reaction cross sections on Ge are of importance to determine Ge production during the astrophysical slow neutron capture process. We present new resonance data on Ge(n,) reactions below 70 keV neutron energy. We calculate Maxwellian averaged cross sections, combining our data below 70 keV with evaluated cross sections at higher neutron energies. Our stellar cross sections are in agreement with a previous activation measurement performed at Forschungszentrum Karlsruhe by Marganiec et al., once their data has been re-normalised to account for an update in the reference cross section used in that experiment.
後神 利志*; 江端 健悟; 藤田 真奈美; 原田 健志; 長谷川 勝一; 細見 健二; 市川 裕大; 今井 憲一*; Kim, S.; 七村 拓野; et al.
EPJ Web of Conferences, 271, p.11002_1 - 11002_7, 2022/11
In the K1.8 beam-line at Hadron Experimental Facility of J-PARC, a new magnetic spectrometer S-2S is being installed. S-2S was designed to achieve a high momentum resolution of 
in FWHM. Several strangeness-physics programs which require the high resolution will be realized by S-2S. The present article introduces J-PARC E70 (missing-mass spectroscopy of 
Be) and E94 (missing-mass spectroscopy of 
Li, 
B, and 
C) experiments.
NH and CaNH thin films by reactive magnetron sputtering under hydrogen partial pressure controlChon, S.*; 福谷 克之; 他8名*
Journal of Physical Chemistry Letters (Internet), 13(43), p.10169 - 10174, 2022/11
被引用回数：0 パーセンタイル：0.00(Chemistry, Physical)Calcium compounds with N and H are promising catalysts for NH
conversion, and their epitaxial thin films provide a platform to quantitatively understand the catalytic activities. Here we report the selective epitaxial growth of CaNH and CaNH thin films by controlling the hydrogen partial pressure (
) during reactive magnetron sputtering. We find that the hydrogen charge states can be tuned by : CaNH containing H
is formed at 
Pa, while CaNH containing H
is formed at 
Pa. In situ plasma emission spectroscopy reveals that the intensity of the Ca atomic emission (422 nm) decreases as increases, suggesting that Ca reacts with H and N to form CaNH at lower , whereas at higher , CaH
is first formed on the target surface and then sputtered to produce CaNH. This study provides a novel route to control the hydrogen charge states in Ca-N-H epitaxial thin films.
Hg and asymmetric fission of neutron-deficient pre-actinidesJhingan, A.*; Andreyev, A. N.; 他28名*
Physical Review C, 106(4), p.044607_1 - 044607_9, 2022/10
被引用回数：8 パーセンタイル：72.81(Physics, Nuclear)Fission of Hg was induced by fusion of 
Xe and 
Fe. The two fragments were detected in coincidence using VAMOS++ supplemented with a new SEcond Detection arm. For the first time in the pre-actinide region, access to the pre-neutron mass and total kinetic energy distributions, and the simultaneous isotopic identification of one the fission fragment, was achieved. The present work describes the experimental approach, and discusses the pre-neutron observables in the context of an extended asymmetric fission island located southwest of 
Pb. A comparison with different models is performed, demonstrating the importance of this new asymmetric-fission island for elaborating on driving effects in fission.
