New Phase of Matter in Multidisciplinary Approach

我们的主要目标是通过阐明强关联物质中超导和磁性有序的新物质相，以及通过多学科方法测量材料的性质来创造独特的材料，从而在材料科学中建立新的概念。我们列举了这个项目取得的显著成果。在CuO_2层中发现了反铁磁性(AFM)和超导电性(SC)的均匀共存相，这使得我们揭示了它们的真实相图，其中包含一个AF量子临界点，这与以前认为的高T_c超导体的载流子掺杂水平的函数相图有很大的不同。揭示了重费米子(HF)化合物CeRhIn_5的温度(T)-压力(P)相图中的一个四临界点。在量子一级相变附近，UGe_2中存在铁磁性和Sc共存的相。发现了新型压致超导体CeNiGe_3和Ce_2Ni_3Ge_5。没有反转对称性的Hf化合物如UIr和CeIrSi3的压致SC的发现表明了一种新的和独特的超导态的可能性。三宅一生等人艾尔已经能够解释HF化合物的高T_c Sc的出现，并解释了它的突然变化。这些关于强关联物质新相的显著发现将使我们对Hf化合物和高T_c超导体中非常规Sc的机制有一个连贯的理解，这是自他们发现以来的一个长期问题。

Our main objectives have established new concepts in materials science through the elucidation of the new phases of matter that underlies the superconductivity and magnetic ordering in strongly correlated matter, and the creation of unique materials, by measuring the properties of the materials in multidisciplinary approach. We list up the remarkable results obtained by this project.1. The discovery of the uniformly coexisting phase of antiferromagnetism (AFM) and superconductivity (SC) in a single CuO_2 layer has lead us to uncover their genuine phase diagram including an AF quantum critical point, which significantly differs from the previously believed phase diagrams as the function of carrier doping level for high-T_c copper-oxides superconductors.2. A tetracritical point in the temperature(T)-pressure(P) phase diagram of the heavy-fermion (HF) compound CeRhIn_5 was unraveled against the previous research results.3. The coexistence phase of ferromagnetism and SC was identified in UGe_2 around a quantum first-order phase transition.4. Novel pressure-induced superconductors CeNiGe_3 and Ce_2Ni_3Ge_5 were discovered.5. The discovery of the pressure-induced SC of HF compounds without inversion symmetry, such as UIr and CeIrSi_3 has pointed to the possibility of a new and unique superconducting state.6. Miyake, et. al. have been able to explain the appearance of high-T_c SC for HF compounds with the sudden change in the. valence number of Ce upon the application of pressure, by a novel anisotropic SC mechanism triggered by the critical valence number fluctuation.These remarkable findings on the new phases of strongly correlated matter would lead us to a coherent understanding of the mechanism of unconventional SC in HF compounds and high-T_c superconductors which is a long-term issue since their discoveries.