Study of the Instability of the Fermi Surface and the Heavy Fermion State around the Quantum Phase Transition for the Pressure-Induced Superconductor

压感超导体量子相变费米面和重费米子态不稳定性研究

• 批准号: 14540337
• 负责人: SETTAI Rikio
• 金额: $ 1.92万
• 依托单位: Osaka Unioversity
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540337/
• 关键词: dHvA effect; Pressure; Heavy Fermion; Pressure-induced Superconductor; Strongly Correlated Electron System; Fermi Surface; Rare Earth Compounds; 量子相転移; 超伝導; CeIn3; CeRhIn5; ドハースファン・アルフェン効果

The character of the 4f-electron in cerium compounds plays an important role on magnetic and charge orderings, spin and valence fluctuations, heavy fermions and anisotropic superconductivity. The de Haas-van Alphen (dHvA) experiment is a powerful tool to study the Fermi surface properties for the 4f-electron systems. For example, the localized 4f-electron character was confirmed in CeB_6,CeIn_3 and CeRhIn_5. On the other hand, the itinerant 4f-electron character was clarified in CeSn_3,CeRu_2Si_2 and CeCoIn_5.In order to clarify the charter of the 4f-electron around the quantum critical point where the magnetic ordering state of an antiferromagnet changes to the paramagnetic one by applying pressure. We have developed the pressure cell for the dHvA experiment under pressure up to 3 GPa. We have studied the change of the Fermi surface properties in antifermmagnets CeRh_2Si_2,CeRhIn_5,CeIn_3 and CePt_3Si.We found the abrupt change of the Fermi surface at the critical pressure P_c in CeRh_2Si_2,CeRhIn_5 and CeIn_3. The change of the Fermi surface indicates that the 4f-electron character is changed from localized to itinerant. Namely, the 4f electron above P_c contributes to the volume of the Fermi surface as the conduction electron. Interestingly, the pressure-induced heavy fermion state with large effective mass was observed around P_c, where the pressure-induced superconductivity appears. We also carried out the dHvA experiments under pressure in CePt_3Si without inversion symmetry in the crystal structure. Although the overall Fermi surface was not observed in CePt_3Si, a new branch with relatively large effective mass was observed above P_c, indicating the change of the electronic state.

铈化合物中 4f 电子的特性对磁和电荷有序性、自旋和价态涨落、重费米子和各向异性超导起着重要作用。德哈斯-范阿尔芬 (dHvA) 实验是研究 4f 电子系统费米表面特性的强大工具。例如，在CeB_6、CeIn_3和CeRhIn_5中证实了局域4f电子特征。另一方面，阐明了CeSn_3、CeRu_2Si_2和CeCoIn_5中4f电子的巡回特征。为了阐明反铁磁体磁有序态转变为顺磁态的量子临界点附近4f电子的规律，施加压力。我们开发了压力传感器，用于压力高达 3 GPa 的 dHvA 实验。我们研究了反铁磁体CeRh_2Si_2、CeRhIn_5、CeIn_3和CePt_3Si中费米表面性质的变化。我们发现CeRh_2Si_2、CeRhIn_5和CeIn_3中费米表面在临界压力P_c处发生突变。费米面的变化表明4f电子特性由局域性变为巡回性。即，P_c上方的4f电子作为传导电子贡献于费米面的体积。有趣的是，在P_c周围观察到具有大有效质量的压力诱导重费米子态，其中出现压力诱导超导。我们还在晶体结构不存在反演对称性的CePt_3Si中进行了压力下的dHvA实验。尽管在CePt_3Si中没有观察到整个费米面，但在P_c上方观察到了有效质量较大的新分支，表明电子态发生了变化。

项目成果

Superconducting Property in CePt3Si under Pressure

• DOI: 10.1143/jpsj.73.1657
• 发表时间: 2004-07
• 期刊: Journal of the Physical Society of Japan
• 影响因子: 1.7
• 作者: Takashi Yasuda;H. Shishido;T. Ueda;Shin Hashimoto;R. Settai;T. Takeuchi;Tatsuma D. Matsuda;Y. Haga;Y. Ōnuki

The High-Pressure Effect of an Electronic State in Uranium Compounds : UNiGa_5 and UN.

铀化合物中电子态的高压效应：UNiGa_5 和 UN。

• 发表时间: 2003
• 期刊: J. Phys. : Condens. Matter 15
• 作者: H.Shishido et al.;R.Settai et al.;H.Shishido;R.Settai et al.;R.Settai et al.;H.Shishido et al.;R.Settai et al.;M.Nakashima;Y.Onuki et al.;T.Yasuda et al.;M.Nakashima et al.;Y.Onuki et al.;T.Ueda et al.;T.Yasuda et al.;R.Settai et al.;Y.Onuki et al.;T.Yasuda et al.;S.Hashimoto et al.;M.Nakashima et al.;R.Settai et al.;S.Araki et al.;Settai et al.;Y.Onuki et al.;M.Nakashima et al.;H.Shishido et al.;R.Asai et al.;M.Nakashima;M.Nakashima et al.
• 通讯作者: M.Nakashima et al.

R.Settai et al.: "De Haas-van Alphen Effect under pressure in UGe2"Journal of Nuclear Science and Technology. supp.3. 94-97 (2002)

R.Settai 等人：“UGe2 压力下的德哈斯-范阿尔芬效应”核科学与技术杂志。

De Haas-Van Alphen experiments under extreme conditions of low temperature, high field and high pressure, for high-quality cerium and uranium compounds.

De Haas-Van Alphen 在低温、高场和高压的极端条件下进行实验，以获得高质量的铈和铀化合物。

• 发表时间: 2003
• 期刊: J.Magn.Magn.Mater. 262
• 作者: H.Shishido et al.;R.Settai et al.;H.Shishido;R.Settai et al.;R.Settai et al.;H.Shishido et al.;R.Settai et al.;M.Nakashima;Y.Onuki et al.;T.Yasuda et al.;M.Nakashima et al.;Y.Onuki et al.;T.Ueda et al.;T.Yasuda et al.;R.Settai et al.;Y.Onuki et al.;T.Yasuda et al.;S.Hashimoto et al.;M.Nakashima et al.;R.Settai et al.;S.Araki et al.;Settai et al.;Y.Onuki et al.;M.Nakashima et al.;H.Shishido et al.;R.Asai et al.;M.Nakashima;M.Nakashima et al.;M.Nakashima et al.;H.Shishido et al.;S.Kirita et al.;R.Settai et al.;H.Shishido et al.;R.Settai et al.
• 通讯作者: R.Settai et al.

H.Shisbido et al.: "A de Haas-van Alphen expemiment under pressure on CeCoIn_5 : deviation from the quantum critical region"J.Phys. : Condens.Matter. 15. L499-L504 (2003)

H.Shisbido 等人：“CeCoIn_5 压力下的 de Haas-van Alphen 实验：偏离量子临界区”J.Phys。