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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：0 パーセンタイル：0.00(Physics, Multidisciplinary)The 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.
山川 光稀*; 西田 明美; 他3名*
日本建築学会構造系論文集, 91(839), p.121 - 132, 2026/01
著者らは、原子力発電所の各階に多数の加速度計を設置する原子力発電所向け多点観測システムを提案した。アトリウムやセットバックなど不規則な形状を持つ建物におけるその有効性を実証するため、このシステムを日本原子力研究開発機構の高温工学試験炉(HTTR)に設置した。本システムによって取得された地震記録の解析により、建物の不規則な形状に起因すると考えられる地震挙動を特定することに成功した。さらに、本研究は、不規則な形状を持つ建物の3次元的な挙動を把握する上で、多点観測システムが有効であることを実証した。
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.
Moon, J. Y.*; 伊藤 由太; 他13名*
Journal of the Korean Physical Society, 87(5), p.640 - 648, 2025/09
被引用回数：2 パーセンタイル：37.23(Physics, Multidisciplinary)A new large-scale heavy-ion accelerator complex, RAON (Rare isotope Accelerator complex for ON-line experiments), in Korea has implemented the state-of-art device, multi-reflection time-of-flight mass spectrometer (MRTOF-MS) for the mass spectrometry of the exotic nuclei. Using the multi-reflections of ions between a pair of grid-free mirror electrodes and therefore extending the fly length, it can achieve the incredibly high mass resolving power of within a short measurement time of 
10 ms, providing the nuclear mass of the exotic nuclei with a high-precision level of sub-ppm. The device is coupled to one of the beamlines in the ISOL experimental hall, ready for participating in the longstanding topics of nuclear structure in the outskirts of the nuclear chart and nucleosynthesis of heavy elements in explosive astrophysical environments. The exclusively high mass resolving power is also advantageous for reducing the isobaric contaminants that rare isotope ion beam facilities suffer from. In this paper, we present a summary of the construction and current performance of the RAON MRTOF-MS.
Cm(
Ti,xn)
Og reaction cross sectionGall, B. J.-P.*; 浅井 雅人; 伊藤 由太; 豊嶋 厚史*; 他30名*
Journal of the Physical Society of Japan, 94(9), p.094201_1 - 094201_9, 2025/09
被引用回数：2 パーセンタイル：44.91(Physics, Multidisciplinary)TiビームをCm標的に照射してOg同位体を探索する実験を理化学研究所の仁科加速器科学研究センターにて実施した。準弾性後方散乱の励起関数から導出した準弾性散乱障壁分布より最適ビームエネルギーを決定した。実験の結果、Og同位体の崩壊は見つからず、1事象検出断面積として0.27pb、1
信頼度の断面積上限値として0.50pbの値を見積もることができた。
巻内 崇彦*; 吉川 貴史; 今井 正樹; 中堂 博之; 齊藤 英治; 他3名*
Physical Review Research (Internet), 7(3), p.033083_1 - 033083_7, 2025/09
Hybridized nuclear and electron spin excitation in a MnCO crystal, a weakly anisotropic antiferromagnet, has been investigated. In this material, the hyperfine interaction is strong enough to form a nuclear spin wave. We measure the microwave absorption induced by magnetic resonance in a bulk MnCO and observe the dispersion representing strong frequency repulsion between electron and nuclear modes due to their hybridization, the signature of nuclear spin wave. Additionally, we observe that the nuclear spin resonance enters a nonlinear regime above a certain excitation power, attributed to the excitation of finite-wavenumber nuclear spin waves.
Fe; Extending the shears mechanism to the 
shell orbitalBasu, S.*; Mukherjee, G.*; 宇都野 穣; 他32名*
Physics Letters B, 868, p.139642_1 - 139642_5, 2025/09
被引用回数：1 パーセンタイル：55.05(Astronomy & Astrophysics)インドのVariable Energy Cyclotron CentreにてFeの高スピン励起状態を生成し、そこからの脱励起ガンマ線を観測した。3136keVの
状態の上に
までの
のバンドが存在し、その
値が大きいこともわかった。そこから磁気回転バンドの存在が確かめられた。殻をバレンス殻にとった殻模型計算を行った結果、この磁気回転バンドは出現しないことがわかり、そこから得られた磁気回転バンドは
軌道へ2個励起した状態が主であると推測された。
/graphene/yttrium iron garnet quadruple heterostructuresChoi, J. W.*; 吉川 貴史; Lee, S.-K.*; 他13名*
Journal of Materials Chemistry A, 13(32), p.26690 - 26699, 2025/08
被引用回数：0 パーセンタイル：0.00(Chemistry, Physical)Strong spin-orbit coupling (SOC) materials and graphene have recently emerged as promising interfacial layers for tailoring spin transport in normal metal/ferromagnet heterostructures. However, spin-to-charge conversion in Pt/two-dimensional (2D) layer/graphene/yttrium iron garnet (YIG) heterostructures remains experimentally unexplored. This study investigates the effects of monolayer graphene and its interfacial coupling with a non-magnetic 2D transition metal dichalcogenide (TMDC) with relatively strong SOC on the longitudinal spin Seebeck effect (LSSE) in Pt/TiSe (or ZrSe)/graphene/YIG quadruple heterostructures. Interfacial SOC between TMDC and graphene is demonstrated to induce an additional spin-to-charge conversion channel in the Pt layer, generating a charge current opposite in direction to the conventional inverse spin Hall effect-induced current from YIG and thereby leading to a net suppression of the LSSE signal. Thus, the study highlights the potential of non-magnetic TMDC interlayers for modulating spin transport, offering new design pathways for spintronic devices.
mesons at finite density using a transport approach in 12 GeV pA reactions市川 真也; Gubler, P.; 成木 恵; KEK-PS E325 Collaboration*; 他25名*
Progress of Theoretical and Experimental Physics (Internet), 2025(9), p.093D01_1 - 093D01_21, 2025/08
被引用回数：2 パーセンタイル：66.10(Physics, Multidisciplinary)The hadron spectrum at finite density is an important observable for exploring the origin of hadron masses. In the KEK-PS E325 experiment, the di-electron decays of mesons inside and outside nuclei were measured using 12 GeV pA reactions. In the previous analysis, a significant excess was observed on the low-mass side of the meson peak in the data for slow-moving mesons (
= 
/
1.25) with the Cu target, and in-medium vector meson spectral modification was verified. We newly employed the PHSD transport approach to take into account the time evolution of spatial density distribution of the target nuclei. Consistent with the previous analysis, a significant excess was observed in the present analysis as well. It was found that incorporating momentum dependence into the spectral modification leads to better agreement with the experimental results. For the slow-moving mesons with the Cu target, the newly obtained modification parameters are consistent with those from the previous analysis within the uncertainties.
Sr and the limits of the 
40 island of deformationRussell, R.*; Smallcombe, J.; 他34名*
Physical Review C, 112(1), p.014309_1 - 014309_7, 2025/07
The region of 
40 has long been associated with strongly deformed nuclear configurations. The presence of this strong deformation was recently confirmed through lifetime measurements in Sr and Zr nuclei. Theoretically, however, these nuclei present a challenge due to the vast valence space required to incorporate all deformation driving interactions. Recent state-of-the-art predictions indicate a near axial prolate deformation for = and = + 2 nuclei between = = 36 and = = 40. In this work, we investigate the shores of this island of deformation through a sub-barrier Coulomb excitation study of the = + 4 nucleus, Sr. Extracting a spectroscopic quadrupole moment of 
(2
) = 0.5
b, we find that Sr is inconsistent with significant axial prolate deformation with a significance of 1.5. This result, albeit with a large uncertainty, indicates that the predicted region of strong prolate deformation around = = 40 is tightly constrained to the quartet of nuclei: 
Sr and 
Zr.
Naeem, M.*; Rehman, A. U.*; Romero Resendiz, L.*; Salamci, E.*; Aydin, H.*; Ansari, P.*; Harjo, S.; Gong, W.; Wang, X.-L.*; 他3名*
Communications Materials (Internet), 6, p.65_1 - 65_13, 2025/04
The need for lightweight materials with mechanical integrity at ultralow temperatures drives the development of advanced alloys for cryogenic use. Additive manufacturing via laser powder bed fusion (LPBF) offers a scalable way to create alloys with tailored properties. Here, we show that LPBF-processed Al10SiMg exhibits a high ultimate tensile strength (395 MPa) and uniform elongation (25%) at 15 K. These enhancements stem from grain refinement, increased geometrically necessary dislocations, and stress partitioning between the Al matrix and the stiffer Si phase, aiding strain accommodation. 
neutron diffraction reveals that the Si phase, with its higher yield strength, bears most of the load, while the Al matrix undergoes continuous strain hardening, extending deformation capacity. These results highlight Al10SiMg's promise for cryogenic applications such as hydrogen storage, aerospace, and quantum computing hardware.
-ray spectroscopy toward the proton dripline; The Curious case of 
ArBeck, T.*; 宇都野 穣; 他13名*
Physical Review C, 111(4), p.044306_1 - 044306_7, 2025/04
被引用回数：0 パーセンタイル：0.00(Physics, Nuclear)米国超伝導サイクロトロン研究所にて陽子過剰な不安定核Arのインビームガンマ線分光実験を行い、新たに1900keVの脱励起ガンマ線を見つけた。これは3767(5)keVの励起準位が存在することを表す。この原子核の鏡像核であるSiで最も近い励起準位は4231(1)keVであり、この2つの原子核のペアにおける鏡像対称性が著しく破れていることがわかった。殻模型計算を行った結果、
殻から
殻に2粒子2空孔励起した状態が多く含まれた状態ではないかと考えられる。
関野 裕太*; 松尾 衛; 他3名*
Physical Review A, 111(3), p.033312_1 - 033312_14, 2025/03
被引用回数：1 パーセンタイル：46.01(Optics)We study magnon-driven spin and heat transport in a magnetic linear junction (MLJ) formed by two ferromagnets in optical lattices linked via linearly aligned bonds.
with 
= 2.1 K revealed by 
Te NMR松村 拓輝*; 徳永 陽; 酒井 宏典; 神戸 振作; 他13名*
Physical Review B, 111(9), p.094507_1 - 094507_9, 2025/03
被引用回数：3 パーセンタイル：71.29(Materials Science, Multidisciplinary)To investigate the intrinsic magnetic properties of UTe, we performed Te-NMR measurements on the ultra-clean single-crystalline UTe with superconducting transition temperature = 2.1 K and compared the results with those of the = 1.6 K sample. The broadening of the linewidth of the NMR spectrum in the a-axis magnetic field and the low-temperature magnetic fluctuations observed in the 1.6 K sample are suppressed in the ultra-clean sample, indicating that such magnetic properties originate from a tiny amount of U deficiency. The present results suggest that the magnetic properties in UTe are sensitive to the U deficiency. We also observed a peculiar angular dependence of the NMR quantities due to large magnetic anisotropy with the a-axis as the magnetic easy axis.
GeTe homojunctions小幡 玲二*; 齊藤 英治; 吉川 貴史; 他13名*
Advanced Materials, 37(8), p.2411459_1 - 2411459_11, 2025/02
被引用回数：10 パーセンタイル：93.08(Chemistry, Multidisciplinary)Twistronics, a novel engineering approach involving the alignment of van der Waals (vdW) integrated two-dimensional materials at specific angles, has recently attracted significant attention. Novel nontrivial phenomena have been demonstrated in twisted vdW junctions (the so-called magic angle), such as unconventional superconductivity, topological phases, and magnetism. However, there have been only few reports on integrated vdW layers with large twist angles 
, such as twisted interfacial Josephson junctions using high-temperature superconductors. Herein, vdW homojunctions of the thin-magnetic flakes, Fe
GeTe
(FGT), with large ranging from 0 to 90 deg, without inserting any tunnel barriers are assembled. Nevertheless, these vdW homojunctions exhibit tunnel-magnetoresistance (TMR) like behavior (pseudo-TMR (PTMR) effect) with the ratios highly sensitive to the values, revealing that the vdW gap at the junction interface between the twisted FGT layers behaves like a tunnel barrier and the serves a control parameter for PTMR by drastically varying magnitudes of the lattice-mismatch and the subsequent appearance of antiferromagnetic (AFM) spin alignment. First-principles calculations considering vacuum gaps indicate strong dependence of TMR on the driven by the sixfold screw rotational symmetry of bulk FGT. The present homojunctions hold promise as a platform for novel AFM spin-dependent phenomena and spintronic applications.
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; 鈴谷 賢太郎; et al.
Progress of Theoretical and Experimental Physics (Internet), 2025(2), p.023H02_1 - 023H02_8, 2025/02
被引用回数：1 パーセンタイル：44.91(Physics, Multidisciplinary)JSNS (J-PARC Sterile Neutrino Search a t J-PARC Spallation Neutron Source) is an experiment that is searching for sterile neutrinos via the observation of 
appearance oscillations using neutrinos from muon decay-at-rest. For this search, rejecting cosmic-ray-induced neutron events by Pulse Shape Discrimination (PSD) is essential because the JSNS detector is located above ground, on the third floor of the building. We have achieved 94.95
rejection of neutron events while keeping 92.82
of signal, electron-like events using a data-driven likelihood method. This article will report the PSD technique using the full fiducial volume of the JSNS detector.
堀 順一*; 佐野 忠史*; 高宮 幸一*; 福谷 哲*; 中村 詔司; 名内 泰志*; 他3名*; 他10名*
KURNS-EKR-21, p.10 - 14, 2025/01
本プロジェクト研究「原子炉施設廃止措置に関する基礎的研究」は、原子炉施設の廃止措置を安全且つ効率的に実施するために必要な基盤データの整備及び測定技術の開発を行うことによって、今後の京大研究炉の廃止措置作業に活用すると共に、福島第一原子力発電所で生じた燃料デブリの管理を含めた廃止措置全般の技術開発に資することを目的して、令和4年度から3か年にわたり実施された。本研究プロジェクトは、目的達成のために、7研究課題から構成されており、京都大学および他機関がそれぞれ分担して実施してきた。原子力機構は、「廃止措置における放射性廃棄物核種の核的特性に関する研究」を分担し、廃止措置で問題になる核種の生成量を評価するのに資する中性子断面積データの取得を目的として、数核種を選定してそれらの中性子捕獲断面積の導出に成功した。
HfAlayed, B.*; Page, R. D.*; Joss, D. T.*; Uusitalo, J.*; Qi, C.*; Briscoe, A. D.*; AlAqeel, M. A. M.*; Andel, B.*; Antalic, S.*; Auranen, K.*; et al.
Physical Review C, 110(3), p.034303_1 - 034303_9, 2024/09
被引用回数：2 パーセンタイル：44.78(Physics, Nuclear)Excited states in the neutron-deficient nuclide Hf have been investigated in experiments performed at the Accelerator Laboratory of the University of Jyvaskyla.
C
reaction at 1.8 GeV/
with the Superconducting Kaon spectrometer市川 裕大; 藤田 真奈美; 長谷川 勝一; 今井 憲一*; 七村 拓野; 成木 恵; 佐藤 進; 佐甲 博之; 田村 裕和; 谷田 聖; et al.
Progress of Theoretical and Experimental Physics (Internet), 2024(9), p.091D01_1 - 091D01_13, 2024/09
被引用回数：4 パーセンタイル：58.63(Physics, Multidisciplinary)We conducted a measurement of the inclusive missing-mass spectrum in the C
reaction at an incident beam momentum of 1.8 GeV/. This measurement was carried out utilizing the Superconducting Kaon Spectrometer (SKS) and the K1.8 beamline spectrometer at the Hadron Experimental Hall in J-PARC. Remarkably, our experimental setup yielded an exceptionaly good energy resolution of 8.2 MeV (FWHM), enabling us to observe significant enhancements in the vicinity of the 
Be threshold region. In order to estimate the spectrum information, we employed several fitting parameters assumptions. The best agreement with the spectrum shape was obtained with combining quasi-free (QF) component and two-Gaussian functions, with the experimental resolution being held constant. The peak positions were obtained to be 
(stat.) 
(syst.) MeV and 
(stat.) 
(syst.) MeV. Another model assumption, utilizing quasi-free (QF) and one Breit-Wigner function with 
(stat.) 
(syst.) MeV and 
(stat.) 
(syst.) MeV, also yielded a similar 
value.
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：2 パーセンタイル：44.78(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.
