Heavy fermion state inpressme-indumd superconductor studied by the de Haas-van Alphen effect under pressure

压力下德哈斯-范阿尔芬效应研究重费米子态压实超导体

• 批准号: 17540325
• 负责人: SETTAI Rikio
• 金额: $ 2.45万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17540325/
• 关键词: Pressure-induced superconductor; Heavy fermion; Quantum abase transition; Qunatum critical noint; de Haas-van Alphen effect; Fermi surface; 反強磁性; dHvA効果; 圧力; 超伝導; 強相関電子系; 希土類化合物

The f electrons of cerium compounds exhibit a variety of characteristic features including spin and charge orderings, spin and valence fluctuations, heavy-fermions and anisoiropic superconductivity. In cerium compounds, the Rudemran-Kittel-Kasuya-Yosida (RKKY) interaction and the Kondo effect compete with each other. The RKKY interaction enhances the long-range magnetic order, while the Kondo effect quenches the magnetic moments of the localized f electrons. Most of the cerium compounds order antiferromagnetically with the Neel temperature T_N, because the RKKY interaction overcomes the Kondo effect at low temperatures.Recently, a new aspect of cerium and uranium compounds with magnetic ordering has been discovered. When a pressure P is applied to compounds with antiferromagnetic ordering such as CeCu_2Ge_2, CeIn_3, and CePd_2Si_2, T_N reaches zero at the quantum critical pressure Pc, and superconductivity is observed at around P_c. The transition from the magnetically ordered state to the nonmagnetic state under pressure, crossing the quantum critical point, is the most interesting issue in strongly correlated f electron systems.We have depeloped high pressure cells for the de Haas-van Alphen experiment and electrical resistivity measurement which can be rotated in the magnetic fields, and investigated the heavy fermion state including the pressure-induced superconductor, which are summarized as follows ;1. Discovery of the pressure-induced superconductor CeIrSi_3 and CeCoGe_3 and huge upper critical field with strong coupling behavior2. Split Fermi surface due to antisymmetric spin-orbit interaction based on the non-conetrosymmetric crystal structure in CeTX_3 (T : transition metal, X : Si, Ge).3. Pressure-induced heavy-fermion superconductivity in Ce_2Ni_3Ge_5 and CePt_3Si,4. Pressure phase diagram in a ferromagnet CePtAl and an antiferromagnet CeTl_3

铈化合物的 f 电子表现出多种特征，包括自旋和电荷排序、自旋和价态涨落、重费米子和各向异性超导性。在铈化合物中，Rudemran-Kittel-Kasuya-Yosida (RKKY) 相互作用和近藤效应相互竞争。 RKKY 相互作用增强了长程磁序，而近藤效应则淬灭了局域 f 电子的磁矩。大多数铈化合物在尼尔温度T_N下呈反铁磁性有序，因为RKKY相互作用克服了低温下的近藤效应。最近，人们发现了具有磁有序性的铈和铀化合物的新方面。当对CeCu_2Ge_2、CeIn_3和CePd_2Si_2等具有反铁磁有序性的化合物施加压力P时，在量子临界压力Pc处T_N达到零，并且在P_c附近观察到超导性。在压力下从磁有序态到非磁态的转变，跨越量子临界点，是强相关 f 电子系统中最有趣的问题。我们开发了用于 de Haas-van Alphen 实验和电阻率测量的高压单元其可以在磁场中旋转，并研究了包括压力感生超导体在内的重费米子态，总结如下： 1．压力诱导超导体CeIrSi_3和CeCoGe_3的发现以及具有强耦合行为的巨大上临界场2。基于CeTX_3中的非锥对称晶体结构（T：过渡金属，X：Si，Ge），由于反对称自旋轨道相互作用而导致费米面分裂。3． Ce_2Ni_3Ge_5 和 CePt_3Si 中压力诱导的重费米子超导性，4。铁磁体 CePtAl 和反铁磁体 CeTl_3 中的压力相图

项目成果

Huge Upper Critical Field and Electronic Instability in Pressure-induced Superconductor CeIrSi3 without Inversion Symmetry in the Crystal Structure

• DOI: 10.1143/jpsj.77.073705
• 发表时间: 2008-06
• 期刊: Journal of the Physical Society of Japan
• 影响因子: 1.7
• 作者: R. Settai;Y. Miyauchi;T. Takeuchi;Florence Lévy;I. Sheikin;Y. Ōnuki

Split Fermi surface properties of LaTGe3(T: Transition metal)and PrCoGe3 without the non-centrosymmetric crystal structure

无非中心对称晶体结构的LaTGe3(T：过渡金属)和PrCoGe3的分裂费米面性质

• 发表时间: 2008
• 期刊: J. Phys. Soc. Jpn. 77(印刷中)
• 作者: T. Kawai;et. al.
• 通讯作者: et. al.

The electronic state tuned by high pressure in a ferromagnet CePtA1

铁磁体 CePtA1 中高压调节的电子态

• 发表时间: 2006
• 期刊: Physica B 378
• 作者: T. Ueda;et. al.
• 通讯作者: et. al.

Pressure-Induced Heavy-Fermion Superconductivity in Antiferromagnet CeIrSi3 without Inversion Symmetry

• DOI: 10.1143/jpsj.75.043703
• 发表时间: 2006-04
• 期刊: Journal of the Physical Society of Japan
• 影响因子: 1.7
• 作者: I. Sugitani;Y. Okuda;H. Shishido;Tsutomu Yamada;A. Thamizhavel;E. Yamamoto;Tatsuma D. Matsuda;Y. Haga;T. Takeuchi;R. Settai;Y. Ōnuki

De Haas-van Alphen effect in CeTI_3 under pressure

压力下 CeTI_3 中的德哈斯-范阿尔芬效应

• 发表时间: 2007
• 作者: R.;Settai
• 通讯作者: Settai