Anomalous Metallic State near the Mott Transition

莫特转变附近的异常金属态

• 批准号: 07237105
• 负责人: SATO Masatoshi
• 金额: $ 100.29万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-07237105/
• 关键词: Mott transition; high temperature superconductivity; anomalous metallic state; spin gap; strongly correlated electrons; 2次元強相関電子系; 超伝導対称性

In the temperature(T) and carrier concentration phase diagram of high-TィイD2cィエD2 Cu oxides, the anomalous metallic phase (AMP), in which various physical properties exhibit unusual behavior can be found in the region near the "half-filled" Mott insulating phase, or in the region T< TィイD20ィエD2 (P) (p*pィイD20ィエD2, T0(pィイD20ィエD2)=ィイD20ィエD2), where p is the concentration of holes doped into the "half-filled" state. The coincidence of the p-region of the AMP with the superconducting p-region clearly indicates that detailed knowledge on this AMP is essentially important for the understanding of the origin(s) of the superconductivity. From this view point experiments have been carried out to study the physical behavior of high- TィイD2cィエD2 oxides and other related systems, where neutron scattering, NMR, angle-resolved photoemission, optical measurements, STM/STS and other various methods have been applied. As the results of the studies, it has been clarified that the anomalous properties in the … More AMP are closely connected with the antiferromagnetic correlation and the singlet formation which begin to grow at around TィイD20ィエD2 with decreasing T. At around the so-called spin-gap temperature TィイD2SGィエD2 (< TィイD20ィエD2), the singlet correlation dominates over the antiferromagnetic one and therefore effects of the spin gap become significant in various quantities. The supercondunting transition is further suppressed down to TィイD2cィエD2 (<TィイD2SGィエD2) in the underdoped region by the fluctuating nature of the orderparaxneter.The physical picture on the singlet formation described above indicates that the origin of the superconductivity is closely related with the large exchange interaction J among the Cu spins and the d-wave symmetry of the order parameter is naturally understood.Besides the studies on high-TィイD2cィエD2 systems, various achievements have been obtained : Superconductivity has been discovered in a doped ladder system under high pressure. Superconductivity which is possibly exotic has also been found is SrィイD22ィエD2RuOィイD24ィエD2. Behavior which indicates the spin-charge separation has been found in quasi one dimensional spin system by angle-resolved photoemission studies. Extensive studies on the metal-insulator transition in transition metal oxides and sulfides have also been carried out. Less

在高温超导体D_2C_（20）Cu氧化物的温度（T）-载流子浓度相图中，在“半填充”Mott绝缘相附近或T< T_（20）T_（20）T_（20）Cu_（20）Cu氧化物的温度（T）-载流子浓度相图中，可以发现异常金属相（AMP），其各种物理性质表现出异常行为。（p*pイD20 D2，T0（pイD20 D2）=イD20 D2），其中p是掺杂到“半填充”状态的空穴浓度。AMP的p区与超导p区的重合清楚地表明，对AMP的详细了解对于理解超导性的起源至关重要。从这一观点出发，已经进行了实验来研究高温氧化物D_2C_xD_2氧化物和其他相关系统的物理行为，其中中子散射、NMR、角分辨光电子能谱、光学测量、STM/STS和其他各种方法已经被应用。作为研究结果，已经阐明， ...更多信息 AMP与反铁磁关联和单重态的形成密切相关，单重态的形成开始于T_（20）~ T_（20）。在所谓的自旋能隙温度T D2 SG D2（< T D20 D2）附近，单重态关联超过反铁磁关联，因此自旋能隙的影响在各种数量上变得显著。超电导转变被进一步抑制到T D2c D2上述单重态形成的物理图象表明，超导电性的起源与Cu自旋和d-自旋之间的大交换相互作用J密切相关。除了对高温超导D_2c → D_2体系的研究外，还取得了多方面的成果：在高压下发现了掺杂梯形体系的超导性;超导体可能是外来的也已被发现是Sr D22 D2 RuO D24 D2。用角分辨光电能谱研究了准一维自旋系统中的自旋-电荷分离现象。对过渡金属氧化物和硫化物中的金属-绝缘体转变也进行了广泛的研究。少

项目成果

S.Uchida: "High Tc Superconductivity and the C_<60> Family" Gordon and Breach Publishers, 354 (1995)

S.Uchida：“高温超导和 C_<60> 系列”Gordon and Breach Publishers，354 (1995)

M.R.Norman et al.: "Destruction of the Fermi Surface in Underdoped High-T_C Superconductors"Nature. 392. 157-160 (1998)

M.R.Norman 等人：“欠掺杂高温超导体中费米表面的破坏”自然。

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T.Hanaguri 等人：“Bi_2Sr_2CaCu_2O_<8 y> 中柱管缺陷对约瑟夫森等离子体共振的影响”Phys.Rev.Lett.. 78. 3177-3180 (1997)

S.Sugai et al.: "Phonon and Two-Magunon Raman Scattering In Pb_2Sr_2Ho(Y)_<1-x>Ca_xCu_3O_<8+δ>"Physica C. 263. 363-366 (1996)

S. Sugai 等人：“Pb_2Sr_2Ho(Y)_<1-x>Ca_xCu_3O_<8+δ> 中的声子和二马古农拉曼散射”Physica C. 263. 363-366 (1996)

J.M.Tranquada et al.: "Neutron-Scattering Study of Stripe-Phase Order in La_<1.48>Nd_<0.4>Sr_<0.12>CuO_4"Phys.Rev.B. 54. 7489-7499 (1996)

J.M.Tranquada 等人：“La_<1.48>Nd_<0.4>Sr_<0.12>CuO_4 中条纹相顺序的中子散射研究”Phys.Rev.B。