Development of novel atomic layer superconductor based on fermiology by spin-resolved ARPES

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H01160
• 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: Tohoku University
• Principal Investigator: Takahashi Takashi 東北大学, 材料科学高等研究所, 学術研究員 (00142919)
• Co-Investigator(Kenkyū-buntansha): 菅原 克明 東北大学, 理学研究科, 准教授 (70547306)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: スピン分解光電子分光 / 分子線エピタキシー / 高温超伝導体 / トポロジカル絶縁体 / 遷移金属ダイカルコゲナイド / 原子層物質 / ディラック半金属 / トポロジカル超伝導

Outline of Final Research Achievements

In order to improve the efficiency of materials development based on the electronic structure, we have constructed a platform in which an ultrahigh-resolution spin-resolved photoemission spectroscopy system, an atomic layer thin film fabrication MBE system, and a sample evaluation chamber are operated in conjunction with each other under the same ultrahigh vacuum condition. We have fabricated various atomic layer materials and their junctions, such as iron-based high-Tc superconductors, transition metal chalcogenides, high-Tc superconductor hybrids, and topological insulator hybrids. By using the platform, we have immediately observed their electronic structures by ARPES experiments without contamination by exposure to air. Our definitive and accurate experiment has provided much knowledge about the mechanism of high-Tc superconductivity, physical properties of 2D superconductors, and topological superconductivity.

Free Research Field

光電子固体物性学

Academic Significance and Societal Importance of the Research Achievements

本研究で構築した原子層プラットフォームにより、鉄系高温超伝導の超伝導機構が薄膜内の電子間相互作用によるものであることや、Pb/TlBiSe2において表面ディラック電子状態が6-7nmもの長さでPb薄膜内に到達していることを見出しことは、超伝導物性の新しい知見として大変意義深い。また、プラットフォームが技術的に確立したことで、ARPESに限らず他の様々な実験で原子層物質の測定が可能となり、今後、原子層物質の物性の解明やデバイスへの応用研究が大きく発展することが期待される。