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荒木 康史; 家田 淳一
Applied Physics Letters, 128(9), p.092406_1 - 092406_7, 2026/03
The spin Hall effect in a heavy metal intercorrelates an AC electric current to the magnetization dynamics in an adjacent ferromagnet, which manifests as an electric reactance in the system's current-voltage response. We present a comprehensive theoretical analysis for this emergent reactance contribution in the frequency regime relevant to transport measurements up to a few GHz. Our analysis reveals that the reactance becomes inductor-like at low frequency below the ferromagnetic resonance. Crucially, we find that the sign of the reactance is directly governed by the spin transfer mechanism at the interface, which depends on the competition between its damping-like and field-like components parametrized by the spin mixing conductance. This characteristic behavior in the reactance offers a powerful transport observable in distinguishing the interfacial spin transfer processes in spintronic materials.
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.
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。
-ordered FePt thin films studied by angle-dependent X-ray magnetic circular dichroism芝田 悟朗; 池田 啓祐*; 高梨 弘毅; 藤森 淳*; 他8名*
Applied Physics Letters, 127(14), p.142406_1 - 142406_6, 2025/10
被引用回数:0 パーセンタイル:0.00(Physics, Applied)We have investigated the contribution of the Fe
electrons to its magnetic anisotropy energy by angle-dependent X-ray magnetic circular dichroism at the Fe
edge. By this technique, one can deduce the magnetic dipole moment
, which represents the anisotropic spatial distribution of spin-polarized electrons, and the orbital moment anisotropy (OMA) of Fe
electrons. Detected finite
indicates that the spin-polarized Fe
electrons are distributed preferentially in the out-of-plane direction of the films. This
of Fe overwhelms the positive contribution of OMA to PMA, and reduces the PMA of
-ordered FePt thin films, consistent with a previous first-principles calculation. The present result implies that a large positive contribution of the non-magnetic element Pt rather than Fe governs the PMA of
-ordered FePt thin films.

社本 真一; Shin, K.*; 赤津 光洋*; 今井 正樹; 植田 大地*; 横尾 哲也*; 根本 祐一*; Hassan, A. M. A.*; Chang, L.-J.*; 家田 淳一; et al.
Applied Physics Letters, 127(13), p.132403_1 - 132403_5, 2025/09
被引用回数:0 パーセンタイル:0.00(Physics, Applied)FeTiO
is an ilumenite antiferromagnetic insulator with Fe
. Two-dimensional ferromagnetic honeycomb layers are antifferomagnetically stacked along the
-axis. The magnetic Bragg peak intensity is enhanced by ultrasound injection up to 300 % on the FeTiO
crystal at low temperatures. The large enhancement is attributed to the large spin-lattice coupling of Fe
in FeTiO
. The enhancement is lost above 35 K, suggesting that the energy splitting of the Fe
levels by the spin-orbit coupling is about 35 K. This finding opens a possibility for high efficiency acoustic spin pumping.

芝田 悟朗; 他9名*
Applied Physics Letters, 126(24), p.241902_1 - 241902_6, 2025/06
被引用回数:0 パーセンタイル:0.00(Physics, Applied)We performed hard X-ray photoemission spectroscopy (HAXPES) experiments of bulk single-crystalline InGaZnO
(sc-IGZO), which was recently synthesized via the optical floating zone method, in order to reveal the bulk intrinsic electronic structure. We find that oxygen vacancies are preferentially located around In atoms in as-grown crystals, which are filled out by post-annealing in an oxygen atmosphere. The subgap states near the valence-band maximum (VBM) were much weaker than those in the previous study even without oxygen annealing, which suggests that the loss of crystallinity is relevant to the formation of them in addition to the oxygen vacancies.
Huang, Y.-C.*; 吉川 貴史; 他5名*
Applied Physics Letters, 126(9), p.092403_1 - 092403_6, 2025/03
被引用回数:0 パーセンタイル:0.00(Physics, Applied)The application of spin-current volume effect (SVE) with volume magnetostriction of iron gallium (FeGa) films is examined for micro-diaphragm actuation. A silicon diaphragm measuring 1.5
1.5 mm
is coated with Pt (100-nm-thick) and FeGa (100-nm-thick) thin films. An alternating charge current passed through the FeGa/Pt/Si diaphragm under a magnetic field perpendicular to the charge current generates an alternating spin current via the spin Hall effect in the Pt film, transferring angular momentum from the Pt film to the FeGa film. The injected spin current provides energy and changes the effective temperature, thereby varying the thermal fluctuation of the magnetic moments. In a magnetic material with volume magnetostriction, the thermal fluctuation of the magnetic moments affects its volume. When the spin fluctuations change, the volume magnetostriction induces a corresponding expansion or contraction of the material. Both electrodeposited and ion-beam sputter-deposited FeGa films are investigated, and it is observed that the FeGa film exhibits SVE. The force generated by the SVE is evaluated based on the vibration amplitude at the fundamental resonant mode. This study demonstrates that the force generated by the SVE is correlated with the volume magnetostriction and the deposition process.
杉山 仁志*; 加藤 謙一*; 関根 直子*; 関根 由莉奈; 渡邉 友亮*; 深澤 倫子*
Chemical Physics Letters, 856, p.141655_1 - 141655_8, 2024/12
被引用回数:16 パーセンタイル:96.04(Chemistry, Physical)ハイドロゲル中の水の構造に対する高分子側鎖の疎水性の影響を調べるために、DSCとXRD測定を実施した。ポリアクリルアミド(PAA)ゲルに含まれる中間水の量はポリ-
-ジメチルアクリルアミド(PDMAA)と比べて少量であった。PAAゲルの場合、束縛水はポリマー鎖表面に存在しているのに対して、PDMAAゲルでは架橋因子として機能していることが明らかになった。
中田 悠人; 佐々木 岳彦*; Thomsen, B.; 志賀 基之
Chemical Physics Letters, 845, p.141285_1 - 141285_9, 2024/06
被引用回数:0 パーセンタイル:0.00(Chemistry, Physical)密度汎関数理論とメタダイナミクスシミュレーションを用いて、シリカ担持白金触媒およびパラジウム触媒を用いた熱水中でのセロビオース加水分解とグルコース水素化反応を研究した。その結果、セロビオースの加水分解は、金属に吸着した水素原子またはシリカに流出したプロトンの攻撃によって進行し、グルコースを形成することがわかった。グルコースは、白金/水界面に吸着した水素原子によって水素化され、ソルビトールを形成する。白金/水界面における加水分解と水素化の反応障壁は、いずれもパラジウム/水界面における反応障壁よりも低い。このことは、白金がパラジウムよりも優れた触媒として機能するという実験結果を説明する。
Yao, D.*; 松尾 衛; 横山 毅人*
Applied Physics Letters, 124(16), p.162603_1 - 162603_5, 2024/04
被引用回数:10 パーセンタイル:79.69(Physics, Applied)We propose a mechanism of spin current generation under an external electric field due to chiral phonons in a chiral-structure superconductor based on the Bogoliubov de Gennes and the Boltzmann equations.
-Ga
O
(001)Tsai, Y. H.*; 小畠 雅明; 福田 竜生; 谷田 肇; 小林 徹; 山下 良之*
Applied Physics Letters, 124(11), p.112105_1 - 112105_5, 2024/03
被引用回数:4 パーセンタイル:53.37(Physics, Applied)Recently, gallium oxide (Ga
O
) has attracted much attention as an ultra-wide bandgap semiconductor with a bandgap of about 5 eV. In order to control device properties, it is important to clarify the chemical state of dopants and doping sites. X-ray absorption near edge structure (XANES) and hard X-ray photoemission spectroscopy were used to investigate the dopant sites and chemical states of Sn in Sn-doped
-Ga
O
(001) samples. The results show that the chemical state of the Sn dopant is the Sn
oxidation state and that the bond lengths around the Sn dopant atoms are longer due to the relaxation effect after Sn dopant insertion. Comparison of experimental and simulated XANES spectra indicates that the octahedral Ga substitution site in
-Ga
O
(001) is the active site of the Sn dopant.
社本 真一; 赤津 光洋*; Chang, L.-J.*; 根本 祐一*; 家田 淳一
Applied Physics Letters, 124(11), p.112402_1 - 112402_5, 2024/03
被引用回数:2 パーセンタイル:29.63(Physics, Applied)Y
Fe
O
における超音波注入によるマグノン励起を非弾性中性子散乱によって研究した。その結果、縦波と横波の両方で超音波注入によりマグノン励起の非弾性中性子散乱強度が増強されることがわかった。
Fe
O
川本 陽*; 吉川 貴史; 齊藤 英治; 他9名*
Applied Physics Letters, 124(13), p.132406_1 - 132406_7, 2024/03
被引用回数:6 パーセンタイル:67.80(Physics, Applied)Magnon spin currents in the ferrimagnetic garnet Tb
Fe
O
with 4
electrons were examined through the spin-Seebeck effect and neutron scattering measurements. The compound shows a magnetic compensation, where the spin-Seebeck signal reverses above and below 
= 249.5(4) K. Unpolarized neutron scattering unveils two major magnon branches with finite energy gaps, which are well explained in the framework of spin-wave theory. Their temperature dependencies and the direction of the precession motion of magnetic moments, i.e., magnon polarization, defined using polarized neutrons, explain the reversal at 
and decay of the spin-Seebeck signals at low temperatures. We illustrate an example that momentum- and energy-resolved microscopic information is a prerequisite to understand the magnon spin current.
Zhou, X.*; 福谷 克之; 他9名*
Applied Physics Letters, 124(8), p.082103_1 - 082103_7, 2024/02
被引用回数:8 パーセンタイル:76.61(Physics, Applied)Electron-doping Mottronics within correlated vanadium dioxide opens up a paradigm to abruptly regulate the Mottronic phase transitions via adjusting the
-orbital occupancy and configuration. Nevertheless, the potential impact of high-valence elementary substitution in the hydrogen-associated Mottronic transitions of VO
is yet unclear. Herein, we demonstrate the role of high-valence elementary substitution in regulating the hydrogen-triggered Mottronic transitions of VO
, assisted by quantitative hydrogen analysis using the nuclear reaction analysis. Substituting vanadium with a high-valence transitional metal within doped-VO
largely reduces the hydrogen incorporation compared to the intrinsic VO
under the low temperature hydrogenation process. Therefore, in contrast to hydrogen-induced electron localization of intrinsic VO
upon low-temperature hydrogenation, only the hydrogen-triggered metallic state is observed within the hydrogen-associated phase diagram of W
V
O
, as further probed by the near-edge X-ray absorption fine structure analysis and X-ray photoelectron spectroscopy. The present work reveals the overlooked role associated with the donor substitutions that largely influences the competitive equilibrium between the two rival hydrogen-induced Mottronic transitions within VO
toward either the metallic or the highly insulating phase.
松島 悠*; Zhang, Z.*; 大橋 由梨*; 畠山 紘*; Xiao, G.*; 船戸 匠*; 松尾 衛; 海住 英生*
Applied Physics Letters, 124(2), p.022404_1 - 022404_7, 2024/01
被引用回数:6 パーセンタイル:67.80(Physics, Applied)We report the discovery of a stepwise magnetic field-induced emergent magneto-inductance effect in Permalloy thin films deposited on polycarbonate substrates. This study opens up exciting avenues for advancing our understanding of emergent inductance in fundamental physics and paves the way for practical applications in flexible magnetic devices.
Tei, C.; 大高 雅彦; 桑原 大介*
Chemical Physics Letters, 829, p.140755_1 - 140755_6, 2023/10
被引用回数:1 パーセンタイル:7.21(Chemistry, Physical)固体金属粒子の界面に付着した液体ナトリウムの核磁気共鳴(NMR)信号を初めて検出することに成功した。本研究では、液体ナトリウムと液体ナトリウム中に浮遊する金属粒子との相互作用の違いによる緩和時間の違いを確認した。その結果、微小チタン粒子表面と液体金属ナトリウムは化学的ではなく物理的に相互作用していることが明らかとなった。
neutron diffraction study on the deformation behavior of the plastic inorganic semiconductor Ag
SWang, Y.*; Gong, W.; 川崎 卓郎; Harjo, S.; Zhang, K.*; Zhang, Z. D.*; Li, B.*
Applied Physics Letters, 123(1), p.011903_1 - 011903_6, 2023/07
被引用回数:5 パーセンタイル:42.64(Physics, Applied)Bulk Ag
S is a plastic inorganic semiconductor at room temperature. It exhibits a compressive strain greater than 50%, which is highly different from brittle conventional counterparts, such as silicon. Here, we present the experimental investigation of the deformation behavior in a plastic inorganic semiconductor Ag
S using
neutron diffraction during compressive deformation at room and elevated temperatures. At room temperature, the lattice strain partitioning among
-orientated grain families could be responsible for the significant work-hardening behavior in the bulk Ag
S with a monoclinic structure. The rapid accumulation of lattice defects and remarkable development of the deformation texture suggest that dislocation slip promotes plasticity. At 453 K, a monoclinic phase transforms into a body-centered cubic phase. A stress plateau appears at
-4.8 MPa, followed by a rehardening state. The deformation mode of bulk Ag
S at the initial stage is likely attributable to the migration of silver ions, and as strain increases, it is closer to that of room temperature, leading to rehardening.
榊原 涼太郎*; Bao, J.*; Yuhara, Keisuke*; 松田 啓太*; 寺澤 知潮; 楠 美智子*; 乗松 航*
Applied Physics Letters, 123(3), p.031603_1 - 031603_4, 2023/07
被引用回数:8 パーセンタイル:60.37(Physics, Applied)ステップバンチング現象の逆であるステップアンバンチング現象について報告する。4H-SiC(0001)表面を高温でアニールすると、隣接するステップの運動の速度が異なるためにステップバンチングが生じ、数ナノメートル以上の高さのステップが生じる。本研究ではAr/H
雰囲気中での水素エッチングによって得られたステップが、その後低温でアニールされると、より低い高さのステップに「アンバンチング」されることを見出した。この「束にならない」現象は、エネルギー論と動力学との間の競合の結果としてうまく説明できる。本発見は、水素エッチングによるSiCの表面平滑化のための別のアプローチを提供し、SiCパワーデバイスや二次元材料成長技術全般への応用に重要な洞察を与える可能性がある。
Meng, L.*; Wang, B.*; Wang, G.-J.*; Zhu, S.-L.*
Physics Reports; A Review Section of Physics Letters, 1019, p.1 - 149, 2023/05
被引用回数:182 パーセンタイル:96.97(Physics, Multidisciplinary)Chiral symmetry and its spontaneous breaking play an important role both in the light hadron and heavy hadron systems. The chiral perturbation theory (
PT) is the low energy effective field theory of the Quantum Chromodynamics. In this work, we shall review the investigations on the chiral corrections to the properties of the heavy mesons and baryons within the framework of
PT. We will also review the scatterings of the light pseudoscalar mesons and heavy hadrons, through which many new resonances such as the D*s0(2317) could be understood. Moreover, many new hadron states were observed experimentally in the past decades. A large group of these states is near-threshold resonances, such as the charged charmoniumlike
and
states, bottomoniumlike
states, hidden-charm pentaquark
and
states and the doubly charmed
state, etc. They are very good candidates of the loosely bound molecular states composed of a pair of charmed (bottom) hadrons, which are very similar to the loosely bound deuteron. The modern nuclear force was built upon the chiral effective field theory (LEFT), which is the extension of the
PT to the systems with two matter fields. The long-range and medium-long-range interactions between two nucleons arise from the single-and double-pion exchange respectively, which are well constrained by the chiral symmetry and its spontaneous breaking. The short-distance interactions can be described by the low energy constants. Such a framework works very well for the nucleon-nucleon scattering and nuclei. In this work, we will perform an extensive review of the progress on the heavy hadronic molecular states within the framework of LEFT. We shall emphasize that the same chiral dynamics not only govern the nuclei and forms the deuteron, but also dictates the shallow bound states or resonances composed of two heavy hadrons.
by monolayer hexagonal boron nitride coating for improved photo- and thermionic-cathodes山口 尚登*; 遊佐 龍之介*; Wang, G.*; Pettes, M. T.*; Liu, F.*; 津田 泰孝; 吉越 章隆; 虻川 匡司*; Moody, N. A.*; 小川 修一*
Applied Physics Letters, 122(14), p.141901_1 - 141901_7, 2023/04
被引用回数:8 パーセンタイル:60.37(Physics, Applied)単層BMをコートしたLaB
の仕事関数の低減に関して報告する。hBNでコートされた領域は、非被覆あるいはグラフェンコートされたLaB
(100)単結晶領域に比べて仕事関数が低下していることが、光電子顕微鏡(PEEM)および熱電子顕微鏡(TEEM)実験から分かった。グラフェンコートに比べてhBNコートされたLaB
(100)では、非常に大きな仕事関数の低下が起きることが、DFT計算から定性的に分かった。計算に酸化層を考慮すると、計算と実験の間の整合性が改善された。放射光XPSによって、我々のLaB
表面に酸化層が実在することを確認した。