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Zhang, A.*; Deng, K.*; Sheng, J.*; Liu, P.*; Kumar, S.*; 島田 賢也*; Jiang, Z.*; Liu, Z.*; Shen, D.*; Li, J.*; et al.
Chinese Physics Letters, 40(12), p.126101_1 - 126101_8, 2023/12
被引用回数：2 パーセンタイル：57.37(Physics, Multidisciplinary)In a Dirac semimetal, the massless Dirac fermion has zero chirality, leading to surface states connected adiabatically to a topologically trivial surface state as well as vanishing anomalous Hall effect. Recently, itis predicted that in the nonrelativistic limit of certain collinear antiferromagnets, there exists a type of chiral "Dirac-like" fermion, whose dispersion manifests four-fold degenerate crossing points formed by spin-degenerate linear bands, with topologically protected Fermi arcs. Here, by combining with neutron diffraction and first-principles calculations, we suggest a multidomain collinear antiferromagnetic configuration, rendering the existence of the Fermi-arc surface states induced by chiral Dirac-like fermions.
BaCo(PO
)Sheng, J.*; Wang, L.*; Candini, A.*; Jiang, W.*; Huang, L.*; Xi, B.*; Zhao, J.*; Ge, H.*; Zhao, N.*; Fu, Y.*; et al.
Proceedings of the National Academy of Sciences of the United States of America, 119(51), p.e2211193119_1 - e2211193119_9, 2022/12
被引用回数：4 パーセンタイル：56.47(Multidisciplinary Sciences)Although considerable progress has been made in the theoretical understanding of the low-dimensional frustrated quantum magnets, experimental realizations of a well-established scaling analysis are still scarce. This is particularly true for the two-dimensional antiferromagnetic triangular lattices. Owing to the small exchange strength, the newly discovered compound NaBaCo(PO) provides a rare opportunity for clarifying the quantum criticality in an ideal triangular lattice with quantum spin S=1/2. In addition to the establishment of the complete phase diagrams, the spin Hamiltonian with a negligible interplane interaction has been determined through the spin wave dispersion in the polarized state, which is consistent with the observation of a two-dimensional quantum critical point with the Bose-Einstein condensation of diluted free bosons.
Harries, J.; 下條 竜夫*; 本間 健二*; 國分 美希*; Sullivan, J. P.*; Lebech, M.*; 東 善郎*
Journal of Physics B; Atomic, Molecular and Optical Physics, 44(9), p.095101_1 - 095101_7, 2011/05
被引用回数：9 パーセンタイル：43.96(Optics)We have studied the production of long-lived, highly-excited, neutral hydrogen atom fragments following oxygen 1s inner-shell excitation/ionization of gas-phase water molecules using synchrotron radiation. Striking differences to fragment ion and low-
neutral H yields are observed close to threshold. To investigate the decay pathways involved the neutral fragments were also detected in coincidence with H
, O
, O, and OH fragments.
波多江 仰紀; Howard, J.*; 海老塚 昇*; 吉田 英次*; 中塚 正大*; 藤田 尚徳*; 成原 一途*; 山田 一博*; 舟場 久芳*; 平野 洋一*; et al.
Journal of Physics; Conference Series, 227, p.012002_1 - 012002_6, 2010/06
被引用回数：2 パーセンタイル：66.79(Physics, Applied)We have developed new technologies for an advanced Thomson scattering diagnostics to meet various requirements for understanding physical phenomena in fusion plasmas. These technologies for the advanced Thomson scattering diagnostics may contribute future Thomson scattering diagnostics. For example, a polarization interferometer is applicable for T
measurement with wide range and imaging measurement. A multipass Thomson scattering and high average power laser employing SBS-PCM may improve the S/N ratio and repetition rate for the measurement, and allows measurement with high spatial resolution. An SBS-PC is a promising technology for LIDAR to generate short laser pulse. A Cr, Nd:YAG will be used for high-efficiency and high average power laser system. Fully relativistic formulae will contribute to the spectrum analysis with wide Te range. A guideline to optimize wavelength channels will be useful for a design of spectrometer.
fluorescence following O(1s) excitation/ionisation in gas-phase water moleculesHarries, J.; 下條 竜夫*; Sullivan, J. P.*; 東 善郎*
no journal, ,
本研究では水分子の酸素原子の内殻(1s)電子の軟X線励起・イオン化に伴う分子の解離過程について新しい情報を得た。O1s電子を励起・イオン化させると中性励起状態の水素原子が生成される。生成される状態分布について情報を得ることによって光解離過程ダイナミクスの解明に繋がる。水分子の電子を励起させると内殻穴のH
Oイオンコアが生成される。このイオンが不安定でオージェ過程が起こる。残るHOイオンが解離して、解離フラグメントの一つが最初に励起された電子をキャプチャーする可能性がある。このフラグメントが Hだと中性の水素原子が生成される。本研究では放射光のパルス性を用いて、その中性状態の原子が基底状態に降りるときに出る紫外線蛍光光子を時分割で検出し、励起状態の分布について情報を得ることに成功した。
