NMR Study on Metal-Insulator Transition and High T_c Superconductivity

金属-绝缘体转变和高温超导的核磁共振研究

• 批准号: 07044045
• 负责人: KUMAGAI Ken-ichi
• 金额: $ 1.41万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07044045/
• 关键词: NMR; High-T_c Superconductor; Strongly correlated electorons; Metal-Insulator Transition; Magnetizm

In this project, unusual electronic properties of the strongly correlated systems such as quaternary compound YNi_2B_2C and RPt_2B_2C have been investigated by NMR measurements. The enhancements of T_1T and Knight shift of ^<11>B at low temperature show an importance of the effects of 3d spin fluctuations in the superconducting YNi_2B_2C families.We have also prepared some Cu Spinel compounds (i.e. CuIr_2S_4 etc.)with enriched isotope of ^<33>S,spin ladder(VO)_2P_2O_7, NdBa_2Cu_3O_7and BaPb_<1-x>Bi_xO_3 with ^<137>Ba. With using of these isotopes, we have successfully observed NMR signals at the atomic sites, which have been investigated at the first time. Magnetic and local electronic states at the Metal-Insulator transition have been discussed.

本项目利用核磁共振技术研究了四元化合物YNi_2B_2C和RPt_2B_2C等强关联体系的电子性质。低温下^ B的T_（1-T）和Knight位移的增强<11>表明了3d自旋涨落效应在YNi_2B_2C族超导体中的重要性。δ <33>S、（VO）_2P_2O_7、NdBa_2Cu_3O_7和BaPb_<1-x>Bi_xO_3与δ <137>Ba的富集同位素。利用这些同位素，我们首次成功地在原子位置上观察到了核磁共振信号。讨论了金属-绝缘体转变时的磁态和局域电子态。

项目成果

熊谷健一、松田祐司、Y.Matsuda,M.B.Gaifullin,K.Kumagai,K.Kadowaki,and T.Mochiku,: ""Collective Josephson Plasma Resonance in the Vortex State of Bi_2Sr_2CaCu_2O_<8+delta>"" Phys.Rev.Lett.75,. 4512-4515 (1995)

Kenichi Kumagai、Yuji Matsuda、Y.Matsuda、M.B.Gaifullin、K.Kumagai、K.Kadowaki 和 T.Mochiku，：“Bi_2Sr_2CaCu_2O_<8+delta> 涡旋态下的集体约瑟夫森等离子体共振” Phys.Rev。快报75，4512-4515（1995）

Y.Matsuda, M.B.Gaifullin, K.Kumagai, K.Kadowaki, and T.Mochiku: ""Collective Josephson Plasma Resonance in the Vortex State of Bi_2Sr_2CaCu_2O_<8+delta>" Phys. Rev. Lett." 75. 4512-4515 (1995)

Y.Matsuda、M.B.Gaifullin、K.Kumagai、K.Kadowaki 和 T.Mochiku：“Bi_2Sr_2CaCu_2O_<8 delta> 涡旋态下的集体约瑟夫森等离子体共振”Phys. Rev. Lett。

熊谷健一、K.Kumagai,S.Tsuji,T.Hagino and S.Nagata: "NMR Studies of Superconductivity and Metal-Insulator Transition in Cu spinel CuM_2X_4 (M=Rh,Ir and x=S,Se)" Spectroscopy of Mott-Insulators and Correlated Metal (Springer Verlag,). 255-264. (1995)

Kenichi Kumagai、K. Kumagai、S. Tsuji、T. Hagino 和 S. Nagata：“Cu 尖晶石 CuM_2X_4 (M=Rh,Ir 和 x=S,Se) 中超导性和金属-绝缘体转变的 NMR 研究”莫特光谱-绝缘体和相关金属（Springer Verlag，）255-264（1995）。

Y.Matsuda, T.Nagaoka, G.Suzuki, K.Kumagai, M.Suzuki, M.Sera, M.Hiroi, and N.Kobayashi: ""Hall Anomaly in the Vortex State of La_<2-x>Sr_xCuO_<4・>", Phys. Rev." B52. R15749-15752 (1995)

Y.Matsuda、T.Nagaoka、G.Suzuki、K.Kumagai、M.Suzuki、M.Sera、M.Hiroi 和 N.Kobayashi：“La_<2-x>Sr_xCuO_< 涡旋态中的霍尔异常” 4・>“物理修订版 B52”（1995 年）

T.Hagino,Y.Seki,N.Wada,S.Tsuji,T.Shirane,K.Kumagai,and S.Nagata: "Superconductivity in Spinel-Type Compounds CuRh2S4 and CuRh2Se4" Phys.Rev.B. 51. 12673-12684 (1995)

T.Hagino、Y.Seki、N.Wada、S.Tsuji、T.Shirane、K.Kumagai 和 S.Nagata：“尖晶石型化合物 CuRh2S4 和 CuRh2Se4 中的超导性”Phys.Rev.B。