Magnetism and Superconductivity in Highly Correlated Systems

高度相关系统中的磁性和超导性

• 批准号: 03044037
• 负责人: FUKUYAMA Hidetoshi
• 金额: $ 4.48万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03044037/
• 关键词: High Tc; Oxides; Heavy electrons; Organic conductors; Quantum wires; t-J model; Hubbard model; Mott transition; ハバ-ド模型; 近藤格子; アンダ-ソン模型; tーJ模型; 重い電子; 銅酸化物

The aims of this project are to explore the electronic states and resulting properties of strongly correlated systems, which include high Tc cuprates. oxides in general, heavy electrons, organic conductors and quantum wires.1.High Tc CupratesThe magnetic excitations and transport properties are successfully investigated based on the t-J model (Fukuyama, Nagaosa). A new proposal has been based on the origin of the mysterious insulating state of PrBa_2Cu_3O_7(Rice).2.Oxides. Mott transitionDetailed numerical calculations have been carried on the two-dimensional Hubbard model, which elucidate that the effective mass diverges as the Mott transition is approached (Imada). Since this is not seen in cuprates, this finding casts doubt on the validity of the Hubbard model to high Tc oxides and hence two different types of Mott transition have been proposed (Imada).3.Heavy ElectronsThe phase diagram of one-dimensional dense Kondo system has been explored by both analytical and numerical method (Ueda). The possibility of the de Haas van Alphen oscillation in the anisotropic superconducting state has been pointed out (Miyake).4.Discovery of Exact SolutionsExact solutions of the extended range t-J model have been found (Kuramoto) and explored (Kuramoto, Kawakami).5.Organic ConductorsUnusual properties of (DCNQI)2Cu have been explained based on the Peierls transition with strong correlations (Fukuyama).6.Quantum WiresIn quantum wires made of semiconductors, electrons form one-dimensional band and hence the Tomonaga-Luttinger liquid. The tunneling characteristics and transport properties have been investigated. (Nagaosa, Fukuyama).

该项目的目的是探索强相关系统的电子态和由此产生的特性，其中包括高 Tc 铜酸盐。一般氧化物、重电子、有机导体和量子线。1.高Tc铜酸盐基于t-J模型（Fukuyama，Nagaosa）成功研究了磁激发和输运特性。一项新的提议基于 PrBa_2Cu_3O_7(Rice).2.Oxides 神秘绝缘态的起源。莫特转变在二维哈伯德模型上进行了详细的数值计算，该模型阐明了有效质量随着接近莫特转变而发散（Imada）。由于这在铜氧化物中没有出现，这一发现对哈伯德模型对高 Tc 氧化物的有效性产生了怀疑，因此提出了两种不同类型的莫特转变（Imada）。3.重电子一维致密近藤的相图系统已通过分析和数值方法（上田）进行了探索。已经指出了各向异性超导状态下德哈斯范阿尔芬振荡的可能性（Miyake）。4.精确解的发现扩展范围 t-J 模型的精确解已经被发现（Kuramoto）并进行了探索（Kuramoto，Kawakami）。5 .有机导体(DCNQI)2Cu 的不寻常性质已基于具有强相关性的 Peierls 转变进行了解释 (Fukuyama)。6.量子线在由半导体制成的量子线中，电子形成一维带，从而形成朝永-卢廷格液体。研究了隧道效应和传输特性。 （长坂，福山）。