Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
C; Inelastic neutron scattering study玉造 博夢; 村上 洋一*; 倉本 義夫*; 佐賀山 基*; 松浦 直人*; 川北 至信; 松石 聡*; 鷲尾 康仁*; 井下 猛*; 浜田 典昭*; et al.
Physical Review B, 102(22), p.224406_1 - 224406_5, 2020/12
Magnetic excitations in layered electride YC have been found by inelastic neutron scattering. We have observed weak but clear magnetic scattering around the wave number 
, but no magnetic order down to the lowest temperature measured (7 K). The imaginary part of the dynamical susceptibility deduced is well described by the Lorentz function of energy 
for each momentum 
. The width 
of the Lorentzian is proportional to 
with 
at 
K. We have also found that with increasing the magnetic form factor decays faster than that of a 
electron in a single Y atom, which indicates a more extended magnetic moment in YC. These results provide experimental evidence that the itinerant magnetism in YC originates from the anionic electrons that reside in the interlayers. The Curie-Weiss-like behavior of the magnetic susceptibility reported in YC is ascribed to the mode coupling effects of spin fluctuations.
Zhang, D.*; Hu, X.*; Chen, T.*; Abernathy, D. L.*; 梶本 亮一; 中村 充孝; 古府 麻衣子; Foley, B. J.*; Yoon, M.*; Choi, J. J.*; et al.
Physical Review B, 102(22), p.224310_1 - 224310_10, 2020/12
The long carrier lifetime and defect tolerance in metal halide perovskites (MHPs) are major contributors to the superb performance of MHP optoelectronic devices. Large polarons were reported to be responsible for the long carrier lifetime. Yet microscopic mechanisms of the large polaron formation, including the so-called phonon melting, are still under debate. Here, time-of-flight inelastic neutron scattering experiments and first-principles density-functional theory calculations were employed to investigate the lattice vibrations (or phonon dynamics) in methylammonium lead iodide, a prototypical example of MHPs. Our findings are that optical phonons lose temporal coherence gradually with increasing temperature which vanishes at the orthorhombic-to-tetragonal structural phase transition. Surprisingly, however, we found that the spatial coherence is still retained throughout the decoherence process. We argue that the temporally decoherent and spatially coherent vibrations contribute to the formation of large polarons in this metal halide perovskite.
anomaly川上 洋平*; 原田 正康*; 岡 眞; 鈴木 渓
Physical Review D, 102(11), p.114004_1 - 114004_9, 2020/12
ダイクォーク描像をもとに作られたカイラル有効理論に基づいて、ヘビークォークを1個含むバリオン励起状態の崩壊幅を計算した。その結果、軸性U(1)対称性をあらわに破るアノーマリーの効果が、崩壊の結合定数を大きく減らすため、幅が10倍程度抑制されることを発見した。
Fleurence, A.*; Lee, C.-C.*; Friedlein, R.*; 深谷 有喜; 吉本 真也*; 向井 孝三*; 山根 宏之*; 小杉 信博*; 吉信 淳*; 尾崎 泰助*; et al.
Physical Review B, 102(20), p.201102_1 - 201102_6, 2020/11
被引用回数：0最近、2次元の二重三角格子において、そこに内在するカゴメ格子によってフラットバンドが出現することが予測された。本研究では、ZrB薄膜上に表面偏析したGe原子がその2次元二重三角格子を形成することを報告する。角度分解光電子分光および第一原理計算から、2次元Ge二重三角格子では有意な面内の長距離ホッピングおよび基板との相互作用が存在するにも関わらず、フラットバンドが形成されることが明らかになった。このフラットバンドは、原子配置から生ずるものではなく、電子状態のカップリングに起因する。
O+
Np reactionVermeulen, M. J.; 西尾 勝久; 廣瀬 健太郎; Kean, K. R.; 牧井 宏之; Orlandi, R.; 塚田 和明; Tsekhanovich, I.*; Andreyev, A. N.; 石崎 翔馬*; et al.
Physical Review C, 102(5), p.054610_1 - 054610_11, 2020/11
Fission fragment mass distributions for 23 nuclei (
U, 
Np, 
Pu, 
Am, 
Cm, and 
Bk) were measured using the multi-nucleon transfer approach in the reaction of O+Np, and their excitation-energy dependence was obtained up to a maximum of 70 MeV. Among them, the low energy fission of 
Np, 
Pu, and 
Cm is reported for the first time. The experimental data for all the studied nuclei were compared to the Langevin calculations. The calculation which takes into account the effects of multi-chance fission well reproduced the peak-to-valley ratio and mass-asymmetric peak positions of the distributions. The angular momenta given to the fissioning nucleus is also discussed.
decay; The Case of 
Hg 
TlCarroll, R. J.*; Podoly
k, Zs.*; Berry, T.*; Grawe, H.*; Alexander, T.*; Andreyev, A. N.; Ansari, S.*; Borge, M. J. G.*; Brunet, M.*; Creswell, J. R.*; et al.
Physical Review Letters, 125(19), p.192501_1 - 192501_6, 2020/11
The 
decay of Hg into the one-proton hole, one neutron-particle 
Tl
nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions used, with implications for the whole of the 
, 
quadrant of neutron-rich nuclei. While both negative and positive parity states with spin 0 and 1 are expected within the 
window, only three negative parity states are populated directly in the decay. The data provide a unique test of the competition between allowed Gamow-Teller and Fermi, and first-forbidden decays, essential for the understanding of the nucleosynthesis of heavy nuclei in the rapid neutron capture process. Furthermore, the observation of the parity changing 
decay where the daughter state is core excited is unique, and can provide information on mesonic corrections of effective operators.
大場 洋次郎; 足立 望*; 戸高 義一*; Gilbert, E. P.*; 間宮 広明*
Physical Review Research (Internet), 2(3), p.033473_1 - 033473_6, 2020/11
Formation of nanosized spin misalignment was found in pure iron processed by high-pressure torsion straining. The small-angle neutron scattering profiles show that the spin misalignment remains in magnetic field up to 10 T, whereas the magnetization is almost saturated below 1 T based on the magnetic measurement. These results indicates that anomalous magnetic anisotropy is induced in pure iron via the high-pressure torsion straining.
Sb
uncovered by soft X-ray magnetic circular dichroism斎藤 祐児; 藤原 秀紀*; 保井 晃*; 門野 利治*; 菅原 仁*; 菊地 大輔*; 佐藤 英行*; 菅 滋正*; 山崎 篤志*; 関山 明*; et al.
Physical Review B, 102(16), p.165152_1 - 165152_8, 2020/10
被引用回数：0Through a high-precision soft X-ray magnetic circular dichroism (XMCD) study of the intermediate-valence compound SmOsSb, we show our successful approach of revealing unprecedented details of Kondo screening below a characteristic temperature of 
20 K in the paramagnetic phase. The multiplet XMCD structure at the Sm 
edge sensitive to the 4
configuration enabled us to observe a clear difference between the temperature evolution above and below 
with one- and two-component behavior, respectively. Our findings are in strong contrast to the conventional Kondo crossover that coincides with the valence transition, but are qualitatively accounted for by theoretical XMCD predictions combined with the two-fluid phenomenology recently proposed. This work contributes to the large context of Kondo physics that is closely related to quantum criticality in heavy fermion systems.
-wave direct capture and interference effect observed in the 
O
O reaction永井 泰樹*; 木下 充隆*; 井頭 政之*; 延原 由利子*; 牧井 宏之; 三島 賢二*; 嶋 達志*; Mengoni, A.*
Physical Review C, 102(4), p.044616_1 - 044616_8, 2020/10
被引用回数：0We measured the total capture cross section of the OO reaction, as well as partial cross sections leading to the ground (
and first excited (
states in 
O. The measurement was carried out at average neutron energies of 157, 349, 398, 427, 468, 498, and 556 keV by using pulsed neutrons produced via the 
Li
Be reaction and a 
-ray detection system based on an anti-Compton NaI(Tl) spectrometer. We observed the interference effect between the 
resonance state at 4554 keV of O, corresponding to a neutron energy of 411 keV in the center-of-mass system, and a non-resonant contribution in the capture process. The measured partial cross sections are in good agreement with theoretical calculations obtained taking into account the interference between the resonance and a non-resonant p-wave direct radiative capture contribution. Using the present results, together with our previous measurement, we derived the Maxwellian-averaged capture cross sections (MACS) for thermal energies between kT = 5 and 100 keV, key quantities for 
process nucleosynthesis studies in massive stars.
decay of 
Fm
and Fm
, and of their daughter nucleiKhuyagbaatar, J.*; He
berger, F. P.*; Hofmann, S.*; Ackermann, D.*; Burkhard, H. G.*; Heinz, S.*; Kindler, B.*; Kojouharov, I.*; Lommel, B.*; Mann, R.*; et al.
Physical Review C, 102(4), p.044312_1 - 044312_8, 2020/10
被引用回数：0Nuclear structure of Fm, Fm, and their daughter nuclei were investigated via detection of their radioactive decays, , , and spontaneous fission. Measured -decay energies, half-lives, and branching ratios improve the literature data significantly. A signature for detection of the hitherto unknown 
Cm was found in the -decay chains from Fm. Two groups of events with average energies of 6.69(2) MeV and 7.01(2) MeV and with a half-life of 
= 300
, s are suggested to originate from Cm. Tentative decay schemes for Fm, 
Cf, Cm, and Fm, 
Cf isotopes are suggested based on the present experimental data. Systematical trends of single-particle states in 
=141 isotones of 
= 92-98 nuclei are discussed.
AuCubiss, J. G.*; Andreyev, A. N.; Barzakh, A. E.*; Manea, V.*; Al Monthery, M.*; Althubiti, N. A.*; Andel, B.*; Antalic, S.*; 他39名*
Physical Review C, 102(4), p.044332_1 - 044332_12, 2020/10
A comprehensive study of the isotope Au has been made at the CERN-ISOLDE facility, using resonance laser ionization. Two long-lived states in Au were identified - a low-spin ground state and a high-spin isomer - each of which were produced as pure beams. Using the ISOLTRAP precision Penning trap, the excitation energy of the isomeric state in Au was determined to be 
189(14) keV. The -decay fine structure patterns of the two states were studied using the Windmill decay station, providing information on the low-lying states in the daughter nucleus 
Ir. Nuclear spin assignments of 
Au
and Au
are made based on the observed -decay feeding and hyperfine structure intensity patterns.
*(2380)Kim, H.*; Kim, K. S.*; 岡 眞
Physical Review D, 102(7), p.074023_1 - 074023_10, 2020/10
被引用回数：0
=0, 
=3のダイバリオン状態の6クォーク(ヘキサクォーク)成分を分析し、質量を求めた。その結果、実験的に報告されている質量をヘキサクォーク構造から矛盾なく説明できることを示した。
仲田 光樹; 高吉 慎太郎*
Physical Review B, 102(9), p.094417_1 - 094417_11, 2020/09
被引用回数：0 パーセンタイル：100(Materials Science, Multidisciplinary)いわゆる光学的Barnett効果[A. Rebei and J. Hohlfeld, Phys. Lett. A 372, 1915 (2008); J. Appl. Phys. 103, 07B118 (2008)], i.e., 円偏光レーザー誘起磁化成長[S. Takayoshi et al., Phys. Rev. B 90, 214413 (2014); S. Takayoshi et al., Phys. Rev. B 90, 085150 (2014)]をフェリ磁性絶縁体に応用し、THz領域におけるマグノン凝縮機構を微視的に解明した。これはBose統計に従うマグノンに特有の巨視的量子効果である。本研究が提供するTHzマグノン凝縮体を活用することで、従来の強磁性絶縁体中のものよりはるかに高速のスピン輸送「巨視的量子干渉効果によるJosephsonスピン流」を実現することができる。
on Pd(210)植田 寛和; 笹川 裕矢*; Ivanov, D.*; 大野 哲*; 小倉 正平*; 福谷 克之
Physical Review B, 102(12), p.121407_1 - 121407_5, 2020/09
被引用回数：0 パーセンタイル：100(Materials Science, Multidisciplinary)Pd(210)表面に化学吸着したHのオルトーパラ転換を報告する。分子線,光刺激脱離,共鳴多光子イオン化法を用いて水素の回転状態変化を調べた。実験結果から、~2秒の転換時間で転換が起こることが明らかになった。実験結果と過去の理論計算結果を比較することで、2次の摂動による転換メカニズムを支持する。
MoCiccarelli, M.*; 湊 太志; 内藤 智也*
Physical Review C, 102(3), p.034306_1 - 034306_9, 2020/09
被引用回数：0 パーセンタイル：100(Physics, Nuclear)The isotope 
Mo, the generator of 
Tc used for diagnostic imaging, is supplied by extracting from fission fragments of highly enriched uranium in reactors. However, a reactor-free production method of Mo is searched over the world from the point of view of nuclear proliferation. Recently, 
Mo production through a muon capture reaction was proposed and it was found that about 50% of Mo turned into Mo through Mo
reaction. However, the detailed physical process of the muon capture reaction is not completely understood. We, therefore, study the muon capture reaction of Mo by a theoretical approach. We used the 
QRPA to calculate the muon capture rate. The muon wave function is calculated with considering the electronic distribution of the atom and the nuclear charge distribution. The particle evaporation process from the daughter nucleus is calculated by the Hauser-Feshbach statistical model. From the model calculation, about 38% of Mo is converted to Mo through the muon capture reaction, which is in a reasonable agreement with the experimental data. It is revealed that negative parity states, especially 
state, play an important role in Mo 
Nb. Isotope production by the muon capture reaction strongly depends on the nuclear structure. To understand the mechanism, excitation energy functions have to be known microscopically.
Bahtiyar, H.*; Can, K. U.*; Erkol, G.*; Gubler, P.; 岡 眞; 高橋 徹*
Physical Review D, 102(5), p.054513_1 - 054513_18, 2020/09
被引用回数：0 パーセンタイル：100(Astronomy & Astrophysics)格子QCDによる第一原理計算を用いて、正負パリティのチャームバリオンの基底および励起状態のスペクトルを求めた。チャームクォークを1個, 2個あるいは3個含むバリオンの正および負パリティ状態の質量を、第一原理計算から求めることで、これまでの実験データや模型計算結果との比較を行い、その物理的な意味を解析することが可能となる。今回の計算では、パイオンの質量が観測値に十分近い物理点に近い領域で、2+1フレーバーのゲージ配位を用いた解析を行った。ディラック行列などの配置の異なる複数の演算子を用意し、その交差相関関数を計算し、固有値を求める方法により、基底状態と励起状態のスペクトルを計算した。
P
rez Snchez, R.*; Jurado, B.*; Mot, V.*; Roig, O.*; Dupuis, M.*; Bouland, O.*; Denis-Petit, D.*; Marini, P.*; Mathieu, L.*; Tsekhanovich, I.*; et al.
Physical Review Letters, 125(12), p.122502_1 - 122502_5, 2020/09
被引用回数：0 パーセンタイル：100(Physics, Multidisciplinary)Reliable neutron-induced-reaction cross sections of unstable nuclei are essential for nuclear astrophysics and applications but their direct measurement is often impossible. The surrogate-reaction method is one of the most promising alternatives to access these cross sections. In this work, we successfully applied the surrogate-reaction method to infer for the first time both the neutron-induced fission and radiative capture cross sections of Pu in a consistent manner from a single measurement. This was achieved by combining simultaneously measured fission and -emission probabilities for the 
Pu(
He, He') surrogate reaction with a calculation of the angular-momentum and parity distributions populated in this reaction. While other experiments measure the probabilities for some selected -ray transitions, we measure the -emission probability. This enlarges the applicability of the surrogate-reaction method.
MnGe (Ga) film via Ge (Ga) 
absorption spectroscopy吉川 智己*; Antonov, V. N.*; 河野 嵩*; 鹿子木 将明*; 角田 一樹; 宮本 幸治*; 竹田 幸治; 斎藤 祐児; 後藤 一希*; 桜庭 裕弥*; et al.
Physical Review B, 102(6), p.064428_1 - 064428_7, 2020/08
被引用回数：0 パーセンタイル：100(Materials Science, Multidisciplinary)X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) spectroscopy were applied at the Ge (Ga) edge to unravel the spin-resolved unoccupied electronic states of CoMnGe (Ga). Complicated spectral features were observed in both XAS and XMCD spectra. For their interpretation, we compared the experimental XAS and XMCD spectra with the calculated Ge (Ga) 4
and 4 orbital partial density of states. The comparison enabled a qualitative explanation of the XMCD spectra as the difference between the majority and minority-spin unoccupied density of states summed over the 4 and 4 orbitals. Our finding provides a new approach to uncover the spin-split partial density of states above the Fermi level.
B
( =Yb, La) observed by multiple-wavelength neutron holography上地 昇一*; 大山 研司*; 福本 陽平*; 金澤 雄輝*; 八方 直久*; 原田 正英; 稲村 泰弘; 及川 健一; 松浦 航*; 伊賀 文俊*; et al.
Physical Review B, 102(5), p.054104_1 - 054104_10, 2020/08
被引用回数：0 パーセンタイル：100(Materials Science, Multidisciplinary)We have succeeded in visualizing the local atomic structures around Sm in B ( =Yb, La), in which a rareearth atom is located in the boron cage, using the newly developed technique for local structure investigations, multiple-wavelength neutron holography in a pulsed neutron facility. From the local atomic structures, we were able to clarify the behavior of Sm in the boron cage. Doped Sm in YbB
fluctuates within the boron cage with a mean displacement of 0.25(4) 
, while that of Sm in LaB is approximately 0.15 . The Sm doping causes the fluctuation of the first-nearest-neighbor B with a mean displacement of 0.28 , while its effect on La, Yb, and the rest of the boron atoms is negligible. These are the first observations of the local behavior of doped rare-earth atoms and B in rare-earth borides with boron cages.
田屋 英俊*; Park, A.*; Cho, S.*; Gubler, P.; 服部 恒一*; Hong, J.*; Huang, X.-G.*; Lee, S. H.*; 門内 明彦*; 大西 明*; et al.
Physical Review C, 102(2), p.021901_1 - 021901_6, 2020/08
被引用回数：0 パーセンタイル：100(Physics, Nuclear)We investigate the hadron production from the vortical quark-gluon plasma created in heavy-ion collisions. Based on the quark-coalescence and statistical hadronization models, we show that total hadron yields summed over the spin components are enhanced by the local vorticity with quadratic dependence. The enhancement factor amounts to be a few percent and may be detectable within current experimental sensitivities. We also show that the effect is stronger for hadrons with larger spin, and thus propose a new signature of the local vorticity, which may be detected by the yield ratio of distinct hadron species having different spins such as 
and 
. The vorticity dependence of hadron yields seems robust, with consistent predictions in both of the hadron production mechanisms for reasonable values of the vorticity strength estimated for heavy-ion collisions.
