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Kreinder, B.; Cox, I.*; Grzywacz, R.*; 西尾 勝久; 他24名*
Nuclear Instruments and Methods in Physics Research A, 1085, p.171298_1 - 171298_7, 2026/05
被引用回数：0In recent experiments, inorganic scintillators have been used to study the decays of exotic nuclei, providing an alternative to silicon detectors and enabling measurements that were previously impossible. However, proper use of these materials requires us to understand and quantify the scintillation process, specifically in response to very heavy nuclei. In this work, we show a simplified method based on the models of Birks (1951) and Meyer and Murray (1962) to parametrize the light output of inorganic scintillators in response to beams of energetic heavy ions over a broad range of energies. We test the accuracy of our parametrization approach by calculating light output and quenching factors for various ions and comparing them with experimental data from Lutetium Yttrium Orthosilicate (LYSO:Ce), a common inorganic scintillator. The Meyer-Murray model suggests that, for sufficiently heavy ions at high energies, the majority of the light output is associated with the creation of delta electrons, which are induced by the passage of the beam through the material. These delta electrons dramatically impact the response of detection systems when subject to ions with velocities typical of beams in modern fragmentation facilities. To illustrate this, we also present a qualitative estimate of the effects of delta rays on overall light output using the Birks-Meyer-Murray parametrization. The approach presented herein will serve as a basic framework for further, more rigorous studies of scintillator response to heavy ions. This work is a crucial first step in planning future experiments where energetic exotic nuclei are interacting with scintillator detectors.
Chen, J.*; 山本 慧; 他13名*
Physical Review Letters, 136(5), p.056702_1 - 056702_8, 2026/02
被引用回数：0The recently developed van der Waals magnets provide a promising platform for spintronics and magnonics. Here, we report the observation of surface magnon propagation in the van der Waals antiferromagnet CrSBr. We find a nearly unidirectional propagation of antiferromagnetic magnon modes, which emerge near the anticrossing of the optical and acoustic magnon bands, in agreement with our theory of magnetostatic waves in antiferromagnets. The propagation direction can be reversed by switching the magnetic field. The observed antiferromagnetic magnons operate in the gigahertz regime due to the weak interlayer exchange coupling. Our results open the pathway for nonreciprocal magnonic applications based on van der Waals antiferromagnets at easily-accessible microwave frequencies.
石飛 尊之; 服部 一匡*
Physical Review Letters, 136(5), p.056402_1 - 056402_6, 2026/02
被引用回数：0We propose purely electronic chirality (pEC), a chiral electronic state that emerges without any structural chirality. As a promising feature, we show that its handedness can be controlled by magnetic fields and illustrate this with a model of 120-degree antiferro quadrupole order on a distorted kagome lattice, relevant to the nonmagnetic ordered phase of URhSn. We also demonstrate that chiral phonons can appear in achiral crystals through coupling to pEC. This provides a new electronic origin of chirality and a basis for studying its connection to structural chirality.
RhZhang, J. Z.*; Chen, Z. Q.*; Qu, T.*; Wang, Y. K.*; Li, Z. H.*; Orlandi, R.; 他62名*
Physics Letters B, 873, p.140144_1 - 140144_9, 2026/02
被引用回数：0At the RIKEN, 
-delayed 
-ray spectroscopy studies were conducted on 
Rh and 
Rh, resulting in the world's first successful identification of a 1/2
isomer in these isotope, extending the energy difference between the 9/2
and 1/2 states up to neutron number 
=74. Comparison of the new results with state-of-the-art calculations suggests that triaxial deformation plays a significant role in the evolution of the energy difference, indicating a shape transition from axially symmetric to triaxial deformation within the Rh isotopic series. These findings provide new insights into the structure of neutron-rich nuclei in the atomic number 
region, elucidating the interplay between triaxial deformation and shell evolution.
遠藤 達朗*; 荒木 康史; 関 宗俊*; 田畑 仁*; 田中 雅明*; 大矢 忍*
Applied Physics Letters, 128(2), p.022405_1 - 022405_6, 2026/01
被引用回数：0 パーセンタイル：0.00(Physics, Applied)Perovskite transition metal oxides (TMOs) are hallmark systems for studying electron correlations, with strong Coulomb interactions reaching the electron volt scale. Such interactions generally hinder coherent charge transport, limiting its observation to only moderately correlated TMOs. Among TMOs with strong electron correlations, the ferromagnetic perovskite manganite La
Sr
MnO
(LSMO) has attracted significant attention for spintronics applications due to its half-metallic nature and robust ferromagnetism, with a Curie temperature above room temperature. In this Letter, we report the emergence of oscillatory conduction in tunnel diodes incorporating an epitaxial thin LSMO layer - a phenomenon not previously observed in strongly correlated oxides. The observed oscillations originate from discrete quantum-well states formed via quantum confinement, indicating coherent transport across the LSMO layer. These quantum-well states are quantitatively explained using a tight-binding model tailored for the electronic structure of LSMO. Our findings demonstrate that high- quality epitaxial perovskite manganites can sustain coherent transport, even in the presence of strong electron correlations, offering avenues for oxide-based quantum and spintronics devices.
Wang, C.*; Yang, Z.*; Ren, Q.*; Mo. X.*; 吉川 貴史; 大門 俊介*; Diao, D.*; 齊藤 英治
Carbon, 246, p.120909_1 - 120909_7, 2026/01
被引用回数：0 パーセンタイル：0.00(Chemistry, Physical)Disordered carbon offers untapped potential for spin caloritronics. We report a phonon-enhanced spin-dependent Seebeck effect (SDSE) in a magnetic carbon film (MCF) with graphene nano-crystallites (10 nm), interfaced with Pt. In a longitudinal setup, the transverse thermoelectric voltage (
) peaks at (
) at 220 K, driven by a thermally induced spin current via the inverse spin Hall effect. Raman spectroscopy reveals a coincident G-band redshift peak, suggesting a phonon-spin resonance unique to MCF's hybrid structure. X-ray absorption spectra confirm stable sp
states, potentially mediating this effect. A multiple-sample study in addition reveals that smaller crystallites enhance SDSE. Unlike pristine graphene or insulators, MCF's weak ferromagnetism and phonon dynamics yield an unconventional spin-thermal regime. This finding redefines carbon's role in spin caloritronics, with tunable nano-crystallite size as a design parameter.
矢野 雅大; 久保 真治; 保田 諭
Chemical Engineering Journal, 528, p.172423_1 - 172423_9, 2026/01
被引用回数：0 パーセンタイル：0.00(Engineering, Environmental)This study presents an in-situ, liquid phase catalytic exchange (LPCE)-based process-intensification approach for hydrogen-isotope separation in proton-exchange membrane water electrolysis (PEM-WE). Supplying water directly to the cathode enables deliberate tuning of the local isotopic composition at the catalyst surface, which in turn enhances both the separation factor and the deuterium enrichment efficiency. A chemical-equilibrium model reproduces these trends by attributing the gain to a thermodynamic shift of the LPCE toward the liquid phase at the cathode. The effectiveness of the method was validated across a wide range of initial deuterium concentrations in the anode feedwater and under high current densities, indicating its versatility. This approach offers a promising and practical strategy for efficient hydrogen isotope separation using PEM-WE.
酒井 英明*; 木俣 基; 他7名*
Nature Communications (Internet), 16, p.11112_1 - 11112_8, 2026/01
被引用回数：0 パーセンタイル：0.00(Multidisciplinary Sciences)We report two-fold nonreciprocal angular magnetoresistance in the tetragonal layered Dirac material SrMnBi
with parity-time-symmetric antiferromagnetic order in its Mn-Bi layers. By quantitatively modelling the angular and field dependencies using a phenomenological framework, we reveal that the observed nonreciprocal interlayer resistivity arises from the current-induced breaking of four-fold rotoinversion symmetry of the Dirac valleys in the Bi square net adjacent to the Mn-Bi layer. Furthermore, we demonstrate the alignment of parity-time-symmetric antiferromagnetic domains via current-field cooling, achieving electric-magnetic control of the f-wave polarity in momentum space. The observed switchable nonreciprocal transport associated with current-tuneable valley nematicity paves the way for novel antiferromagnetic spintronic and valleytronic applications.
山根 結太*; 中根 丈太郎*; 荒木 康史; 家田 淳一
Physical Review B, 113(1), p.014421_1 - 014421_7, 2026/01
被引用回数：0 パーセンタイル：0.00(Materials Science, Multidisciplinary)We theoretically investigate emergent impedance induced by domain-wall dynamics in antiferromagnets. Emergent impedance, arising from a combined action of spin-transfer torque and spinmotive force, was previously predicted and observed in spiral magnets. Here we develop a formalism for the electrical response of an antiferromagnetic domain wall under ac currents, and obtain analytical expressions for the resulting emergent impedance. We find that two dynamical modes play separate roles in the emergent impedance: Translational motion of the domain-wall center generates a contribution proportional to its velocity, analogous to that arising from the corresponding motion of a spiral magnet. Another contribution, unique to antiferromagnetic domain walls, originates from the time-dependent canting of the sublattice magnetizations localized within the moving domain wall, whose magnitude is inversely proportional to the antiferromagnetic exchange coupling constant. The competition between these two distinct contributions determines the sign and magnitude of the imaginary part of the emergent impedance at sub-resonant frequencies. Our results provide a fundamental insight into electron transport in antiferromagnets, and open avenues for novel antiferromagnet-based spintronics devices.
-wave 
baryonsSu, N.*; Chen, H.-X.*; Gubler, P.; 保坂 淳
Physical Review D, 113(1), p.016005_1 - 016005_7, 2026/01
被引用回数：1Using the QCD sum rule method, we investigate the mass splitting for the spin-orbit partner states of the 
baryon assuming that it is a -wave excitation with 
. This study is an extension of a previous work, in which the masses of these states were estimated with uncertainties too large to extract the reliable mass splitting. In the present study, by directly formulating a sum rule for the mass splitting, we obtain an improved prediction, 
MeV. This result provides a more quantitative insight into the spectrum of -wave baryons and serves as a useful reference for future experiments.
藤井 大輔; 川口 眞実也*; 田中 満*
Proceedings of Science (Internet), 500, p.239_1 - 239_6, 2026/01
クォークやグルーオンがハドロンの中に閉じ込められる機構の解明は、QCDにおける最も基本的な課題である。この課題を解決するためには、クォーク凝縮やグルーオン凝縮と、それに伴う自発的対称性の破れのハドロン形成における役割を理解することが重要である。近年、陽子内部の応力分布が実験的に測定できるようになった。これは陽子に対するエネルギー運動量テンソルの行列要素を特徴付ける重力形状因子から抽出される。この応力分布は、クォークやグルーオンをハドロン内部に閉じ込める力そのものであり、応力分布の観点から上記の課題にアプローチする道が拓かれた。本トークでは、クォーク凝縮やグルーオン凝縮など、カイラル対称性やスケール対称性の破れを反映する現象が、核子内部の圧力分布にどのように寄与するかを調べた結果、これらの寄与が核子を安定化させるために不可欠であることを示す。
Shim, S.-I.*; 保坂 淳
Proceedings of Science (Internet), 500, p.010_1 - 010_6, 2026/01
反応によって
粒子の励起状態の生成を調べた結果を報告する。
藤井 大輔; 保坂 淳*; 岩中 章紘*; 酒井 忠勝*; 橘 基*
Proceedings of Science (Internet), 500, p.135_1 - 135_6, 2026/01
強結合QCD物質の理解は、その非摂動的性質のため依然として困難である。われわれは、クォーク質量が非零の二フレーバー・ハードウォール型ホログラフィック模型において、有限密度・零温度のQCDを研究する。高密度相は、一様アンサッツの下で古典的運動方程式を解くことで得る。バルク場と境界観測量を結び付けるため、ホログラフィック正則化を施して対応辞書を構築し、ハードウォールのカットオフにおけるIR境界項が本質的役割を果たすことを強調する。この枠組みで、バリオン数密度が大きくカイラル凝縮が強く抑制されたバリオン物質相を見出す。得られた解から状態方程式を導出し、中性子星の質量半径関係を計算すると、広いパラメータ領域で2太陽質量を超える星が実現し得ることが分かる。
from QCD sum rulesSu, N.*; Chen, H.-X.*; Gubler, P.; 保坂 淳
Proceedings of Science (Internet), 500, p.076_1 - 076_6, 2026/01
We investigate the recently observed baryon using QCD sum rules. By constructing P-wave baryon currents and performing spin projection and parity projection, we obtain the masses of the 
and 
states as 
GeV and 
GeV, in good agreement with experiment. This suggests that is likely to be a negative parity P-wave excited state, though its spin remains undetermined and requires further study of its decay properties.
石川 貴嗣*; 保坂 淳; Gubler, P.; 佐甲 博之; 谷田 聖; 他33名*
Proceedings of Science (Internet), 500, p.225_1 - 225_5, 2026/01
We plan to measure cross sections for pion-induced phi-meson production on the proton at the high-intensity high-momentum secondary-particle beamline at J-PARC under the E95 physics program to study nucleon resonances and a possible hidden-strangeness pentaquark baryon in the phi-nucleon channel, which are expected to appear in the s-channel intermediate state of the reaction. The pentaquark baryon is a candidate for the origin of the unresolved bump that observed in the differential cross section at forward angles for photoproduction of phi mesons on the proton. We use several incident negative-pion momenta ranging from 1.6 to 2.4 GeV/c and detect positive and negative kaon pairs from the phi-meson decays utilizing the existing spectrometer with large acceptance. In this contribution, we will give a brief introduction of this E95 physics program.
Rn/At generator田中 皐*; 清水 悠介*; 井田 朋智*; 鷲山 幸信*; 西中 一朗*; 浅井 雅人; 瀬川 麻里子; 横山 明彦*
Radiochimica Acta, 9 Pages, 2026/00
被引用回数：0 パーセンタイル：0.00(Chemistry, Inorganic & Nuclear)医療用放射性同位元素Atを製造・供給するためのRn/Atジェネレータシステムを開発している。本研究では、Rn/AtジェネレータシステムにおけるRnの気相回収条件を調査するため、溶液中のRnの溶解状況を解析した。硝酸-塩酸混合液中でのBiターゲットの溶解とそれに続く中和により、Rn回収効率が向上することが示された。気相Rn回収率は88%に達し、利用可能なAtの50%が回収されており、今後さらなる向上が期待される。
増田 啓人*; 山根 結太*; 土肥 昂尭*; 山崎 匠*; Modak, R.*; 内田 健一*; 家田 淳一; Kl
ui, M.*; 高梨 弘毅; 関 剛斎*
Advanced Science (Internet), 12(48), p.e14598_1 - e14598_9, 2025/12
被引用回数：0 パーセンタイル：0.00(Chemistry, Multidisciplinary)Current-induced domain-wall motion (CIDWM) in a synthetic antiferromagnet is a key phenomenon for developing potential high-density-packed magnetic domain-wall memory with fast operation. Here, we report CIDWM in the antiferromagnetically-coupled two Co layers through the Ir interlayer sandwiched by the two Pt layers: Pt/Co/Ir/Co/Pt. The top and bottom Pt layers play a role for generating the spin current coming from the spin Hall effect, which gives rise to the dual spin-orbit torque (SOT) acting on the perpendicular magnetizations of the Co layers. Although a simple argument would predict that SOTs from top and bottom Pt layers cancel each other out, the dual SOT nucleates a reversed magnetic domain and drives the CIDWM effectively at current density of the order of 10
A m
. This study also examines the effect of antisymmetric interlayer exchange coupling (AIEC) on CIDWM. We find a positive correlation between the magnitude of AIEC and the domain wall velocity whereas the current density required for nucleating the reversed domain shows a negative correlation with the magnitude of AIEC. These facts suggest that the existence of AIEC improves the performance of CIDWM. Our results provide a new avenue to design SOT domain wall devices based on a synthetic antiferromagnet.
深谷 有喜; 松田 巌*
Applied Physics Letters, 127(26), p.263102_1 - 263102_6, 2025/12
被引用回数：0 パーセンタイル：0.00(Physics, Applied)本研究では、全反射高速陽電子回折(TRHEPD)法を用いて、Ag(111)表面上に成長させたビスマセン(グラフェンのビスマス版)の原子配置を詳細に解析した。ビスマセン由来の回折スポットに着目した結果、[
]および[
]方位に対してペアとなるロッキング曲線のプロファイルに有意な差が認められなかった。これは、ビスマセンが平坦なハニカム格子で構成されていることを示唆する。動力学的回折理論に基づく強度計算を行ったところ、単位胞内の2つのビスマス原子はAg(111)層に対して同一高さに位置していることが明らかになった。さらに、ビスマセンとAg(111)の第一層におけるデバイ温度は、バルク材料と比較して低下していることが判明した。これらの結果は、ビスマセンの特異なトポロジカル特性を理解するための基礎的な構造情報を提供する。
香西 直文; 徳永 紘平; 土肥 輝美; 高橋 嘉夫*
Journal of Environmental Chemical Engineering, 13(6), p.119612_1 - 119612_9, 2025/12
被引用回数：0 パーセンタイル：0.00(Engineering, Environmental)In this study, we achieved pH control (up to 7) of phosphate-based geopolymer hardened bodies by reacting metakaolinite with a mixed aqueous solution of phosphoric acid and a soluble phosphate salt. This pH control was achieved by adjusting the total amount of phosphate ions and varying the molar ratio of phosphoric acid to phosphate salt. The hardened body with a neutral pH of 6.0 displayed mechanical and spectroscopic characteristics considerably similar to those of conventional phosphoric acid geopolymer hardened bodies with a pH below 3. To evaluate its potential application as a radioactive waste solidifier, a Sr-doped hardened body with a neutral pH (using an SrCl aqueous solution as a simulant of 
Sr) was subjected to static leaching testing. The Sr-doped hardened body demonstrated high resistance to Sr leaching. Sr K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy of the Sr-doped hardened body revealed that its high Sr confinement capability was primarily due to inner-sphere complexation of Sr with the phosphate groups bridging metakaolinite particles.
=1/2 Ising-like antiferromagnetic chain CsCoCl in transverse magnetic fields木村 尚次郎*; 大西 弘明; 鳴海 康雄*; 奥西 巧一*; 萩原 政幸*; 金道 浩一*; 菊池 彦光*
Journal of the Physical Society of Japan, 94(12), p.124703_1 - 124703_8, 2025/12
被引用回数：0 パーセンタイル：0.00(Physics, Multidisciplinary)We have performed high-field electron spin resonance (ESR) measurements on the =1/2 Ising-like one-dimensional (1D) antiferromagnet CsCoCl in the frequency range up to 3.1 THz and magnetic fields 
for 
up to 53 T, as well as density-matrix renormalization group (DMRG) calculations. The analysis of the high-field magnetization confirms that the quantum critical point in the transverse field is 
= 60.3 T. The results of the ESR measurements suggest the remarkable behavior that all the excitation branches coming from the Zeeman ladder converge to upon increasing the transverse fields. The ESR measurements with polarized electromagnetic waves show that the ESR absorption lines show clear polarization dependence. The absorption lines, which become soft in the transverse field, are revealed to couple with the magnetic field oscillating parallel to the static magnetic fields. These experimental results are compared with the detailed DMRG calculations.
