Microscopic Investigation of the coexistence state of Magnetism and Superconductivity in Uranium-based Heavy-Fermion Superconductors

铀基重费米子超导体磁性与超导共存状态的显微研究

• 批准号: 20340088
• 负责人: ISHIDA Kenji
• 金额: $ 12.65万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2008
• 资助国家: 日本
• 起止时间: 2008 至 2010
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-20340088/
• 关键词: 磁気共鳴; 重い電子系物質; U系物質; 異方的超伝導状態; 強磁性超伝導体; 核四重極共鳴 NQR; 核磁気共鳴 NMR; 重い電子系超伝導体; ウラン系化合物; 核四重極共鳴NQR; 核磁気共鳴NMR; 重い電子超伝導体; U系化合物

We have studied coexistence of ferromagnetism and superconductivity in ferromagnetic superconductor of UCoGe from the microscopic NMR measurement using a high-quality single crystal. Below the ferromagnetic transition, whole region of the sample is in ferromagnetic state, and a nearly half of the region becomes superconductive below Tc. We also have investigated magnetic fluctuations in the compound, and found that longitudinal ferromagnetic fluctuations along the ordered moments directed to the c axis is dominant at low temperatures. The magnetic fluctuations we observed have been suggested to be favorable for spin-triplet superconductivity from theoretical point of view. These results suggest the possibility that spin-triplet superconductivity is realized in UCoGe.

我们用高质量的单晶进行了微观核磁共振测量，研究了UCoGe铁磁超导体中铁磁性和超导电性的共存。在铁磁相变以下，样品的整个区域都处于铁磁状态，而在T_c以下，近一半的区域成为超导。我们还研究了化合物中的磁涨落，发现在低温下，沿c轴有序矩的纵向铁磁涨落占主导地位。从理论上看，我们观察到的磁涨落对自旋三重态超导电性是有利的。这些结果表明在UCoGe中实现自旋三重态超导电性的可能性。

项目成果

Two-Dimensional Spin Dynamics in the Itinerant Ferromagnet LaCoPO Revealed by Magnetization and 31P-NMR Measurements

• DOI: 10.1143/jpsj.78.113705
• 发表时间: 2009-09
• 期刊: Journal of the Physical Society of Japan
• 影响因子: 1.7
• 作者: H. Sugawara;K. Ishida;Y. Nakai;H. Yanagi;T. Kamiya;Y. Kamihara;M. Hirano;H. Hosono

超伝導と磁性の共存

超导性与磁性的共存

• 发表时间: 2011
• 期刊: パリティ Vol.26 No.1
• 作者: M. Yamashita;N. Nakata;Y. Kasahara;T. Sasaki;N. Yoneyama;N. Kobayashi;S. Fujimoto;T. Shibauchi and Y. Matsuda;石田憲二
• 通讯作者: 石田憲二

<59>^Co-NMRを用いた単結晶UCoGeの異方的磁気励起の研究

<59>^ 利用 Co-NMR 研究单晶 UCoGe 的各向异性磁激发

• 发表时间: 2010
• 作者: 井原慶彦;服部泰佑;軽部皓介;石田憲二;田村暢之;出口和彦;佐藤憲昭;佐藤伊佐務
• 通讯作者: 佐藤伊佐務

^{31}P and ^{75}As NMR evidence for a residual density of states at zero energy in superconducting BaFe_{2}(As_{0.67}P_{0.33})_{2}

• DOI: 10.1103/physrevb.81.020503
• 发表时间: 2009-08
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Y. Nakai;T. Iye;S. Kitagawa;K. Ishida;S. Kasahara;T. Shibauchi;Y. Matsuda;T. Terashima

Anisotropic magnetic fluctuations in the ferromagnetic superconductor UCoGe studied by directional-dependent <59>^Co NMR measurements

通过方向相关的 <59>^Co NMR 测量研究铁磁超导体 UCoGe 中的各向异性磁涨落

• 发表时间: 2010
• 期刊: Physical Review Letter 105
• 作者: Y.Ihara;T.Hattori;K.Ishida;Y.Nakai;E.Osaki;K.Deguchi;N.K.Sato;I.Satoh
• 通讯作者: I.Satoh