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Strong local moment antiferromagnetic spin fluctuations in V-doped LiFeAs

Xu, Z.*; Dai, G.*; Li, Y.*; Yin, Z.*; Rong, Y.*; Tian, L.*; Liu, P.*; Wang, H.*; Xing, L.*; Wei, Y.*; et al.

npj Quantum Materials (Internet), 5(1), p.11_1 - 11_7, 2020/02

 被引用回数:3 パーセンタイル:52.95(Materials Science, Multidisciplinary)

We use neutron scattering to study Vanadium (hole)-doped LiFe$$_{1-x}$$V$$_{x}$$As. In the undoped state, LiFeAs exhibits superconductivity at $$T_mathrm{c} = 18$$ K and transverse incommensurate spin excitations similar to electron overdoped iron pnictides. Upon Vanadium doping to form LiFe$$_{0.955}$$V$$_{0.045}$$, the transverse incommensurate spin excitations in LiFeAs transform into longitudinally elongated ones in a similar fashion to that of potassium (hole)-doped Ba$$_{0.7}$$K$$_{0.3}$$Fe$$_{2}$$As$$_{2}$$ but with dramatically enhanced magnetic scattering and elimination of superconductivity. This is different from the suppression of the overall magnetic excitations in hole-doped BaFe$$_{2}$$As$$_{2}$$ and the enhancement of superconductivity near optimal hole doping. These results are consistent with density function theory plus dynamic mean field theory calculations, suggesting that Vanadium doping in LiFeAs may induce an enlarged effective magnetic moment $$S_mathrm{eff}$$ with a spin crossover ground state arising from the inter-orbital scattering of itinerant electrons.


Spin excitations in optimally P-doped BaFe$$_2$$(As$$_{0.7}$$P$$_{0.3}$$)$$_2$$ superconductor

Hu, D.*; Yin, Z.*; Zhang, W.*; Ewings, R. A.*; 池内 和彦*; 中村 充孝; Roessli, B.*; Wei, Y.*; Zhao, L.*; Chen, G.*; et al.

Physical Review B, 94(9), p.094504_1 - 094504_7, 2016/09


 被引用回数:14 パーセンタイル:61.4(Materials Science, Multidisciplinary)

最適Pドープされた超伝導体BaFe$$_2$$(As$$_{0.7}$$P$$_{0.3}$$)$$_2$$ (T$$_c$$=30K)におけるスピン励起の温度及びエネルギー依存性が非弾性中性子散乱実験を使って調べられた。我々の実験結果は密度汎関数理論や動的平均場理論で予想される計算結果と矛盾しておらず、BaFe$$_2$$(As$$_{0.7}$$P$$_{0.3}$$)$$_2$$における平均プニクトゲン高さの減少が、電子相関の強さを弱め、磁気励起の有効バンド幅の増加に寄与することを示唆している。


ITER magnet systems; From qualification to full scale construction

中嶋 秀夫; 辺見 努; 井口 将秀; 名原 啓博; 松井 邦浩; 千田 豊; 梶谷 秀樹; 高野 克敏; 礒野 高明; 小泉 徳潔; et al.

Proceedings of 24th IAEA Fusion Energy Conference (FEC 2012) (CD-ROM), 8 Pages, 2013/03



Identified charged hadron production in $$p + p$$ collisions at $$sqrt{s}$$ = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; 秋葉 康之*; Al-Bataineh, H.*; Alexander, J.*; 青木 和也*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

 被引用回数:162 パーセンタイル:99.44(Physics, Nuclear)

200GeVと62.4GeVでの陽子陽子の中心衝突からの$$pi, K, p$$の横運動量分布及び収量をRHICのPHENIX実験によって測定した。それぞれエネルギーでの逆スロープパラメーター、平均横運動量及び単位rapidityあたりの収量を求め、異なるエネルギーでの他の測定結果と比較する。また$$m_T$$$$x_T$$スケーリングのようなスケーリングについて示して陽子陽子衝突における粒子生成メカニズムについて議論する。さらに測定したスペクトルを二次の摂動QCDの計算と比較する。


Azimuthal correlations of electrons from heavy-flavor decay with hadrons in $$p+p$$ and Au+Au collisions at $$sqrt{s_{NN}}$$ = 200 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; 秋葉 康之*; Al-Bataineh, H.*; Alexander, J.*; 青木 和也*; Aphecetche, L.*; Aramaki, Y.*; et al.

Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04

 被引用回数:8 パーセンタイル:51.93(Physics, Nuclear)



Measurement of neutral mesons in $$p$$ + $$p$$ collisions at $$sqrt{s}$$ = 200 GeV and scaling properties of hadron production

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review D, 83(5), p.052004_1 - 052004_26, 2011/03

 被引用回数:156 パーセンタイル:98.48(Astronomy & Astrophysics)

RHIC-PHENIX実験で重心エネルギー200GeVの陽子陽子衝突からの$$K^0_s$$, $$omega$$, $$eta'$$$$phi$$中間子生成の微分断面積を測定した。これらハドロンの横運動量分布のスペクトルの形はたった二つのパラメーター、$$n, T$$、のTsallis分布関数でよく記述できる。これらのパラメーターはそれぞれ高い横運動量と低い横運動量の領域のスペクトルを決めている。これらの分布をフィットして得られた積分された不変断面積はこれまで測定されたデータ及び統計モデルの予言と一致している。


Intrabeam scattering at low temperature range

Yu, P.*; He, Z.*; Wei, J.*; Sessler, A. M.*; 岡本 宏巳*; 百合 庸介

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.1943 - 1945, 2010/05

In the process of beam cooling, the main heating source is intra-beam scattering (IBS), in which Coulomb collisions among particles lead to a growth of the beam's 6D phase-space volume. The results of molecular dynamics simulations have shown an increase of heating rate as the temperature increases from absolute zero, then a peak in the heating rate, and subsequent decrease with increasing temperature. On the other hand, in the traditional IBS theory, heating rate increases monotonically as the temperature becomes lower and lower. In this paper, we attempt to extend the traditional IBS theory valid at high temperatures to relatively low temperature range, by including some many-body effects in the traditional IBS theory. In particular, we take into account the static and dynamic effect of the self-electromagnetic field of the beam. We shall show how these effects modify the traditional theory, and present the evaluation of IBS heating rate of an ion beam in the low temperature range.


Beam injection tuning of the J-PARC main ring

Wei, G.; 小関 忠*; 五十嵐 進*; 冨澤 正人*; 高野 淳平*; 石井 恒次*; 白形 政司*; Fan, K.*; 畠山 衆一郎; 魚田 雅彦*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.3915 - 3917, 2010/05

The beam commissioning of J-PARC (Japan Proton Accelerator Research Complex) MR (Main Ring) was started from May 2008 and is in progress. As usual, injection tuning is in the first stage and strongly related to other tuning items. Starting with design schemes, making adjustment due to leakage field influence from injection septum, doing envelope matching considering dilution of beam profile in Main Ring are reported in this papers.


Beam fast extraction tuning of the J-PARC main ring

Wei, G.; 小関 忠*; 冨澤 正人*; 五十嵐 進*; 石井 恒次*; 安東 愛之輔; 高野 淳平*; 魚田 雅彦*; Fan, K.*; 畠山 衆一郎; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.3918 - 3920, 2010/05

The beam commissioning of J-PARC/MR has been started from May 2008 and is in good progress. One key purpose of MR commissioning is the 30 GeV beam fast extraction to neutrino beam line, which reflect the overall commissioning result. In the MR, fast extraction system comprises 5 kickers and 8 septa which give a bipolar kick to neutrino beam line or abort dump. However before commissioning, the measured magnetic field distribution of each fast extraction septa shows non-linear profile along the horizontal direction. In order to find the influence, a beam simulation with the measured field distributions of septa has been performed. Depends on this study and some OPI (Operation Interface) made by code SAD for orbit modification online, fast extraction of 30 GeV beam to neutrino beam line has been achieved on April 23rd 2009. And so far, 100 kW continual operation to neutrino line have been achieved, too.


Status and challenges in beam crystallization

Wei, J.*; Yu, P.*; 岡本 宏巳*; 百合 庸介; Li, X.-P.*; Sessler, A. M.*

Proceedings of Workshop on Beam Cooling and Related Topics (COOL '09) (Internet), p.86 - 90, 2010/00

During the past several decades, beam crystallization has been studied both theoretically and experimentally. Theoretical investigations have been numerical, mainly using computer modeling based on the method of molecular dynamics, and analytical, based on phonon theory. Experimental investigations involve both ion storage rings and ion traps using both electron and laser beam cooling. Topics of interests include crystal stability in various accelerator lattices and under different beam conditions, crystalline beam formation in shear-free ring lattices with both magnets and electrodes, experimental simulation of alternating-gradient conditions with an ion trap, etc. In this paper, we first review theoretical approaches and major conclusions pertaining to beam crystallization. Then, we analyze conditions and methods of the various major experiments. Finally, we discuss, both theoretically and experimentally, some improvements, open questions, and challenges in beam crystallization.


Separation of Am and Cm from HLLW by extraction chromatography using novel R-BTP extraction resins

Wei, Y.*; 星 陽崇; 森田 泰治; Bruggeman, A.*; Goethals, P.*

Proceedings of International Conference on Advanced Nuclear Fuel Cycle; Sustainable Options & Industrial Perspectives (Global 2009) (CD-ROM), p.1086 - 1093, 2009/09



Phonon spectrum and the maintenance condition of crystalline beams

Li, X.-P.*; 榎園 隼人*; 岡本 宏巳*; 百合 庸介; Sessler, A. M.*; Wei, J.*

Physical Review Special Topics; Accelerators and Beams, 9(3), p.034201_1 - 034201_10, 2006/03

 被引用回数:7 パーセンタイル:48.48(Physics, Nuclear)



Structure and optical properties of germanium implanted with carbon ions

Wei, P.; Xu, Y.; 永田 晋二*; 鳴海 一雅; 楢本 洋

Nuclear Instruments and Methods in Physics Research B, 206(1-4), p.233 - 236, 2003/05

 被引用回数:5 パーセンタイル:39.5(Instruments & Instrumentation)



Morphology evolution of thin Ni film on MgO(100) substrate

Lin, C.; Xu, Y. H.; 楢本 洋; Wei, P.; 北澤 真一; 鳴海 一雅

Journal of Physics D; Applied Physics, 35(15), p.1864 - 1866, 2002/08

 被引用回数:10 パーセンタイル:41.77(Physics, Applied)


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