Material synthesis with extremely high electric field on an electrochemical interface

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01038
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: The University of Tokyo
• Principal Investigator: Kazunori Ueno 東京大学, 大学院総合文化研究科, 准教授 (10396509)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 新物質合成 / 超伝導 / スピン軌道相互作用 / イオン液体 / 薄膜 / 電気化学界面

Outline of Final Research Achievements

(1) new transition metal dichalcogenite with layered structure CoTe2 and NiTe2, which do not exist in bulk, were developed as thin films. (2) For germanane thin films, in which germanium is two-dimensional and hydrogen-terminated to be stable in air, we developed two-dimensional Hall gases with very high mobility at low temperatures using electric double-layer transistors. (3) We realized atomic-scale thickness control of SrVO3, a typical metal of transition metal oxides, using electrochemical etching technique. SrNbO3, and SrTaO3, which do not exist in bulk, we observed for the first time the metal-insulator transition from metal to disordered metal and insulator in these ultra-thin films. Furthermore, we found that the Rashba-type spin-orbit interaction that occurs in the ultra-thin films with broken inversion symmetry is very large for oxides.

Free Research Field

物性物理学

Academic Significance and Societal Importance of the Research Achievements

新物質・新材料を開発しようとするとき、一般には室温・大気中で熱力学的に安定な（バルク多結晶として作ることができる）相が研究対象とされる。本研究は熱力学的に不安定で本質的に室温・大気中では存在できない物質を計算科学の力をかりて薄膜としての安定性をしらべ、実際に薄膜として合成した。系統的にこのような物質開発を進めることで、今後、半導体デバイス、スピントロニクスデバイス、超伝導物質などさまざまな応用分野のある新物質が実現できると期待される。