Theoretical study of the mechanism of high-temperature superconductivity and design of new superconductors based on the electron-correlation mechanism

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400380
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Yanagisawa Takashi 国立研究開発法人産業技術総合研究所, 電子光技術研究部門, 上級主任研究員 (90344217)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 強相関係 / 高温超伝導 / 多体波動関数 / モンテカルロ法 / 超伝導機構 / 反強磁性 / 強相関スピンゆらぎ / クロスオーバー

Outline of Final Research Achievements

We investigated the mechanism of high-temperature superconductivity on the basis of electronic models with strong correlation. The cuprate high-temperature superconductors are known as a typical strongly-correlated-electron system. We tried to optimized the wave function of many-electron systems and succeeded to obtain the most optimized wave function. The electronic state was examined by using this wave function. We found that there is a crossover between weakly correlated and strongly correlated regions. In the strongly correlated region, the antiferromagnetic correlation is suppressed and at the same time the superconducting pair correlation is enhanced. This leads to the result that the superconducting transition occurs in the strongly correlated region as a result of crossover from weakly to strongly correlated regions.

Free Research Field

多体量子物理学