Control of conductivity and magnetism of organic devices based on strongly correlated electron systems

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H00891
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 32:Physical chemistry, functional solid state chemistry, and related fields
• Research Institution: Institute for Molecular Science
• Principal Investigator: Yamamoto Hiroshi 分子科学研究所, 協奏分子システム研究センター, 教授 (30306534)
• Co-Investigator(Kenkyū-buntansha): 川椙 義高 東邦大学, 理学部, 講師 (40590964)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 超伝導体 / 基板歪み / 電界効果 / 強相関電子系 / モット絶縁体 / スピントロニクス / キラリティ / CISS効果

Outline of Final Research Achievements

Strongly correlated electron systems, in which conduction electrons interact strongly with each other, can dramatically change their physical properties with changes in minute carrier density and pressure, and exhibit unique functionalities such as high-temperature superconductivity. For this reason, they have attracted attention as electronic materials for some time, but there remain many unresolved aspects of their basic physical properties. In this study, a new strongly correlated electron device using molecular interfaces was fabricated, and the ground-state phase diagram of organic strongly correlated electrons with simultaneous changes in temperature, pressure and carrier density was completed, identifying the parameter space required for superconductivity. Furthermore, spin polarization was generated in the superconducting phase using organic strongly correlated crystals with chiral space groups, and a new superconducting spintronics was proposed.

Free Research Field

分子物性科学

Academic Significance and Societal Importance of the Research Achievements

強相関電子系超伝導体として知られるペロブスカイト型銅酸化物は非常に硬い物質であるため、キャリア密度制御には向いているものの圧力制御による超伝導相探索に向いていなかった。本研究では柔軟な有機分子結晶を用いることにより、圧力とキャリア密度の両者をパラメータとする強相関電子系超伝導の相図を完成させることができたので、超伝導相探索・理論構築における重要な手がかりを与え、将来の超伝導工学・超伝導エレクトロニクスに貢献できると期待される。また今回見出したキラル超伝導体を用いたスピン偏極の生成は、磁石によるキラル分子の分離原理にも踏み込むものであり、今後のキラル物質科学に多くの示唆を与えるものである。