Fermi surface studies near magnetic quantum critical points under high pressure

高压下磁量子临界点附近的费米表面研究

• 批准号: 14340111
• 负责人: TERASHIMA Taichi
• 金额: $ 8.9万
• 依托单位: National Institute for Materials Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 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/en/grant/KAKENHI-PROJECT-14340111/
• 关键词: high pressure; magnetic field; de Haas-van Alphen effect; strong electron correlation; ferromagnetism; superconductivity; Fermi surface; antiferromagnetism; フェルミ面; 圧力; 有機伝導体

1.We have developed piston-cylinder high-pressure cells suitable for de Haas-van Alphen (dHvA) effect measurements at pressures up to 3 GPa, using non-magnetic high-strength alloy NiCrAl.2.We have measured the dHvA effect in the ferromagnetic superconductor UGe_2 up to 〜2 GPa, exceeding the critical pressure, for the magnetic field parallel to the magnetic easy a-axis. We have found that the enhancement of quasiparticle mass at high pressures is not directly related to the ferromagnetic-paramagnetic transition at the critical pressure but is ascribed to the so-called T_x transition.3.We have measured the dHvA effect in ZrZn_2, which was reported to be a ferromagnetic superconductor, at pressures up to -2 GPa. We have found from detailed analyzes of exchange splitting of the Fermi surface a crossover between two magnetic states induced by the magnetic field and have proposed that UGe_2 and ZrZn_2 may have a common temperature-pressure-magnetic-field phase diagram.4.We have measured the dHvA effect in CeIn_3, which exhibits superconductivity near the antiferromagnetic-paramagnetic transition, at pressures up to 〜3 GPa. We have found the appearance of new Fermi surfaces at the critical pressure of the antifermmagnetism and have also found pronounced changes of the Fermi surface at other pressures. Those observations indicate that the change of the electronic structure accompanying the antiferromagnetic-paramagnet is transition occurs successively.

1.我们开发了活塞缸高压电池，适用于压力高达 3 GPa 的德哈斯-范阿尔芬 (dHvA) 效应测量，采用非磁性高强度合金 NiCrAl。2.我们测量了 dHvA 效应我们发现，对于平行于易磁轴的磁场，铁磁超导体 UGe_2 高达 ~2 GPa，超过了临界压力。高压下准粒子质量的增强与临界压力下的铁磁-顺磁转变并不直接相关，而是归因于所谓的 T_x 转变。 3.我们测量了 ZrZn_2 中的 dHvA 效应，据报道，该效应为铁磁超导体，在高达 -2 GPa 的压力下，我们从费米表面的详细编织交换分裂中发现了两种磁态之间的交叉。并提出 UGe_2 和 ZrZn_2 可能具有共同的温度-压力-磁场相图。4.我们测量了 CeIn_3 中的 dHvA 效应，CeIn_3 在压力高达 ~ 3 GPa。我们发现在反铁磁性临界压力下出现了新的费米面，并且还发现了显着的变化。其他压力下的费米表面表明，伴随反铁磁-顺磁体转变的电子结构的变化成功发生。

项目成果

Global Phase Diagram of the Magnetic Field-Induced Organic Superconductors λ-(BETS)_2Fe_xGal-_xCl_4

磁场诱导有机超导体λ-(BETS)_2Fe_xGal-_xCl_4的整体相图

• 发表时间: 2003
• 期刊: Journal of the Physical Society of Japan 72・2
• 作者: S.Uji;T.Terashima他
• 通讯作者: T.Terashima他

Pressure-induced Fermi surface change in quasi-one-dimensional conductor β"-(ET)(TCNQ)

准一维导体β"-(ET)(TCNQ)中压力引起的费米面变化

• 发表时间: 2004
• 期刊: Journal de Physique IV 114
• 作者: S.Yasuzuka;T.Terashima;S.Uji 他
• 通讯作者: S.Uji 他

T.Terashima, S.Uji, 他7名: "Magnetic phase diagram and the pressure and field dependence of the Fermi surface in UGe_2"Physical Review B. 65・17. 174501-1-174501-5 (2002)

T.Terashima、S.Uji 等 7 人：“磁相图以及 UGe_2 中费米表面的压力和场依赖性”物理评论 B. 65・17（2002 年）

Fermi surface studies of the ferromagnetic superconductor UGe_2 under high pressure

高压铁磁超导体UGe_2的费米面研究

• 发表时间: 2003
• 期刊: Acta Physica Polonica B 34
• 作者: T.Yamamizu;et al.;T.Terashima et al.
• 通讯作者: T.Terashima et al.

H.Aoki, T.Terashima, S.Uji, 他3名: "Evolution of Fermi Surface of Strongly Correlated f Electron System under Hydrostatic and Uniaxial Pressures"Journal of Physics : Condensed Matter 14, 10705 (2002). 14・44. 10705-10708 (2002)

H. Aoki、T. Terashima、S. Uji 等 3 人：“静水压和单轴压力下强相关 f 电子系统费米面的演化”《物理学杂志：凝聚态》 14, 10705 (2002)。 10705-10708 (2002)