The study of novel quantum phenomena caused from the competition among multiple ground states in vanadium oxides

钒氧化物中多个基态竞争引起的新量子现象的研究

• 批准号: 18104008
• 负责人: UEDA Yutaka
• 金额: $ 54.58万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (S)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2010
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18104008/
• 关键词: 強相関係; 強相関電子系; 物性実験; バナジウム酸化物; 電磁気物性; 高圧物性; 圧力誘起超伝導; 電化秩序; 金属絶縁体転移; 電荷秩序

Inβ-vanadium bronzes, we found the competition among a rich variety of electronic states such as charge disordered metallic phases, charge ordered antiferromagnetic insulator phases, charge ordered spin-gapped insulator phases and superconducting phases, in pressure-temperature electronic phase diagrams. Metaphorically speaking, the superconductivity is in bloom in the garden with the competition among various ground states. Particularly, the superconductivity which competes with charge order is the first example in transition metal oxides. It is accompanied by the dimensional crossover and the enhancement of charge fluctuation. In hollandite vanadium oxide, the metal-insulator transition was found. It is accompanied by the charge order and the formation of spin singlet V^4+-V^4+ pairs inherent in vanadium oxides. Furthermore, a very unique metal-insulator transition remaining ferromagnetic in the insulator phase was discovered in hollandite chromium oxide.

在β-钒青铜的压力-温度电子相图中，我们发现了电荷无序金属相、电荷有序反铁磁绝缘体相、电荷有序自旋间隙绝缘体相和超导相等多种电子态之间的竞争。比喻地说，在各种基态之间的竞争中，超导性在花园里盛开。特别是在过渡金属氧化物中，与电荷序竞争的超导性是第一个例子。它伴随着量纲交叉和电荷波动的增强。在荷兰酸钒中，发现了金属-绝缘体的转变。它伴随着钒氧化物固有的电荷顺序和自旋单线态V^4+-V^4+对的形成。此外，在荷兰酸铬氧化物中发现了一种非常独特的金属-绝缘体过渡，在绝缘体相中保持铁磁性。

项目成果

DISCOVERY OF THE "DEVIL'S FLOWER" IN A CHARGE-ORDERING SYSTEM-SYNCHROTRON X-RAY DIFFRACTION STUDY OF NaV2O5

电荷有序系统中“魔鬼之花”的发现——NaV2O5同步加速器X射线衍射研究

• 发表时间: 2006
• 期刊: Modern Physics Letter B 20
• 作者: K.Ohwada;Y.Fujii;H.Nakao;Y.Murakami;M.Isobe;Y.Ueda
• 通讯作者: Y.Ueda

Observation of Metal-Insulator Transition in Hollandite Vanadate, K_2V_8O_<16>

菱铁矿钒酸盐 K_2V_8O_<16> 中金属-绝缘体转变的观察

• 发表时间: 2006
• 期刊: J.Phys.Soc.Jpn. 75
• 作者: M.Isobe;S.Koishi;N.Kouno;J.Yamaura;T.Yamauchi;H.Ueda;H.Gotou;T.Yagi;Y.Ueda
• 通讯作者: Y.Ueda

<51>_V unclear spin-lattice relaxation in the quasi-one-dimensional conductor β-Na<0.33>_V_2O_5.

<51>_V 准一维导体 β-Na<0.33>_V_2O_5 中的自旋晶格弛豫不清楚。

• 发表时间: 2006
• 期刊: Physical Review B 74
• 作者: 榎戸輝揚;ほか;小川 光;I.Yamauchi
• 通讯作者: I.Yamauchi

NMR measurements of the quasi-one-dimensional superconductor β-Na_0.33V_20_5 under high pressure using a modified Bridgman anvil cell

使用改进的布里奇曼砧池在高压下对准一维超导体 β-Na_0.33V_20_5 进行核磁共振测量

• 发表时间: 2007
• 期刊: J. Magn. Magn. Mater 310
• 作者: Kozasa;T.;水野信男;T. Kozuka
• 通讯作者: T. Kozuka

^<23>Na NMR study of the Na order-disorder transition in the quasi-one-dimensional conductor β-Na_0.33V_20_5

^<23>准一维导体β-Na_0.33V_20_5中Na有序-无序转变的Na NMR研究

• 发表时间: 2008
• 期刊: Physica B:Condensed Matter 403
• 作者: Kakamu;K.;M. Fukushige;P.Polacik;T.Hams;I. Yamauchi
• 通讯作者: I. Yamauchi