Strongly Correlated Electron Phase under Multiple Environment

[1]强关联电子的性质，[2]受限系统中的关联电子相，[3]超高压下的电子相.[1]强关联电子(Miyake，Kitaoka，OnuK，Suga)的性质发现了临界价态涨落引起超导电性的新机制，提出了UGe_2，UPD_2Al_3，ProS_4Sb&lt；12&GT；，(TMTSF)_2PF_6，CeCu2Si2和CeRhIn5相与反铁磁性共存(Miyake)。利用核磁共振/核磁共振技术，在重费米子(UPT_3和UnI_2Al_3)和氧化Rutenate(Sr_2RuO_4)体系中发现了自旋三重态超导电性，发现了重费米子化合物在加压下反铁磁性和超导电性的微观共存相，多层高温超导体中反铁磁性和超导电性的纳米级共存(Kitaoka)。高品质单哭…更多的Ce和铀化合物已经生长出来，数量超过50个，它们的磁性和费米表面性质已经被阐明(Onuki)。稀土和过渡金属化合物的高分辨(能量和波矢)软X射线光电子能谱在世界上是第一次获得成功，这一体敏技术(Suga)的突破解决了许多争议并将被解决。[2]受限系统(Itoh，CHO，Hiyamizu，One，Ogawa，Nozue)中的关联电子相在强禁闭和弱禁闭状态下，研究了单个纳米结构中激子能量和寿命与激子数目的依赖关系，发现了受限系统中电子关联及其与光学非线性的关系。验证了关联光子系统中光子德布罗意波长的概念(Itoh)。“物质的微观非局域光学响应”这一新的理论方案已经得到高度发展，并被应用于纳米结构及相关系统(CHO)中的各种线性和非线性过程。研究了分子束外延生长的In_&lt；0.1&gt；Ga$_&lt；0.9&gt；As/(GaAs)_6(AlAs)_1量子线激光器在(775)Bμ衬底上的室温振荡，得到了非常均匀的(221)A In&lt；0.22&gt；As/GaAs量子线(平水)。为了创造基于自旋极化电流的新效应，实验研究了自旋极化电流对锰氧化物的磁阻控制、铁磁体对超导体的自旋注入以及电流诱导的磁畴壁运动(ONO)。从理论上研究了多电子系统(Ogawa)光激发非平衡态(Ogawa)的相分离动力学、经典有序和量子有序的形成以及量子多体效应对线性/非线性光学响应的影响。研究发现，分子筛中碱金属团簇的轨道简并对其铁磁性(Nozue)起重要作用。[3]超高压下的电子相(Suzuki，Nasu，Shimizu，Kobayashi)首次证明了在固体氧中，压力诱导的绝缘体-金属转变是通过能带重叠(Suzuki)实现的。进行了高压穆斯堡尔谱测量，阐明了ε-Fe的磁性，它是金属Fe(NaSU)的高压相。已经发展了产生超低温和超高压以及测量物理性质的技术，并在简单的系统中发现了加压超导，如氧、铁、锂和有机分子晶体、离子晶体等(清水)。利用新研制的高压室，在U基重电子化合物和Ce基重电子化合物中发现了压力诱导的磁非磁转变、超导电性和电荷有序，特别是在铁磁超导体UGe_2中，通过热容测量(Kobayashi)确定了超导电性的体相性质。较少

Research was performed in the following three subject : [1] Properties of strongly correlated electrons, [2] Correlated electron phase in confined systems, and [3] Electron phases under ultra-high pressures.[1] Properties of strongly correlated electrons (Miyake, Kitaoka, OnuK, Suga)New mechanism of superconductivity of due to critical valence fluctuations is found, new types of mechanism are proposed for superconductivity in Uge_2, Upd_2Al_3, PrOs_4Sb_<12>, (TMTSF)_2PF_6, and the phase of CeCu_2Si_2 and CeRhIn_5 coexisting with the antiferromagnetism (Miyake). By means of NMR/NQR techniques, spin-triplet superconductivity in heavy-fermion (Upt_3 and Uni_2Al_3) and rutenate oxide (Sr_2RuO_4) systems, microscopic coexisting phase of antiferromagnetism and superconductivity in heavy-fermion compounds under pressure, a nano-scale coexistence of antiferromagnetism and superconductivity in multilayered high-temperature superconductors, have been discovered (Kitaoka). High-quality single cry … More stals of cerium and uranium compounds over fifty in number have been grown, and their magnetic and Fermi-surface properties have been clarified (Onuki). High resolution (energy and wave vector) soft X-ray photoemision spectroscopy of rare earth and transition metal compounds have been succeeded for the first time in the world, and many controversies are solved and going to be solved by this break through of the bulk sensitive technique (Suga).[2] Correlated electron phase in confined systems (Itoh, Cho, Hiyamizu, One, Ogawa, Nozue)Both in the strong and weak confinement regimes, the dependencies of exciton energy and life time upon the number of excitons in a single nano-structure were studied and the evidence of electron correlation in confined systems and its relation with optical nonlinearities were found. The concept of photonic de Broglie wavelength in correlated photon system was verified (Itoh). A new theoretical scheme of "microscopic nonlocal optical response of matter" has been highly developed and applied to various linear and nonlinear processes in nanostructures and related systems (Cho). Room temperature oscillation of MBE-grown In_<0.1>Ga$_<0.9>As/(GaAs)_6(AlAs)_1 quantum wire (QWR) lasers on (775)B GaAs substrates with an emission wavelength range of 0.85μ was demonstrated, and extremely uniform (221)A In_<0.22>Ga_<0.78>As/GaAs quantum wires were fabricated (Hiyamizu). For the purpose of creating novel effects based on spin-polarized current, magnetoresistive control of a manganite by spin-polarized current, spin injection from ferromagnet into superconductor, and current-induced domain wall motion were studied experimentally (Ono). "Photoinduced Phase Transition" was studied theoretically to clarify the phase-separation dynamics, formation of classical and quantum orders, and quantum many-body effects on linear/nonlinear optical responses in photoexcited nonequilibrium states of many-electron systems (Ogawa). The spatial distribution and the electron transport phenomena of edge state in integer and fractional quantum Hall system are found to be strongly affected by the confinement potential, and an orbital degeneracy of alkali metal clusters in zeolite is found to play an important role for its ferromagnetism (Nozue).[3] Electron phases under ultra-high pressures (Suzuki, Nasu, Shimizu, Kobayashi)It has been shown for the first time that the pressure-induced insulator-metal transition in solid oxygen would be realized by band overlapping (Suzuki). High pressure ^<57>Fe Mossbauer measurements have been performed, clarifying the magnetic property of ε-Fe which is a high-pressure phase of metallic Fe (Nasu). Techniques of generating very low-temperature and ultra high-pressure and measuring physical properties have been developed, and superconductivity under pressure was discovered in simple systems, such as oxygen, iron, lithium and organic molecular crystals, an ionic crystal, etc. (Shimizu). By means of newly developed high-pressure cell, the pressure-induced magnetic-nonmagnetic transition, superconductivity and charge-ordering have been found in the U- and Ce-based heavy electron compounds, particularly in the ferromagnetic superconductor Uge_2, the bulk nature of the superconductivity was established by the heat capacity measurements (Kobayashi). Less