Construction of quantum transport theory for spintronic devices and proposal of novel devices

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K03831
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: The University of Tokyo
• Principal Investigator: Kato Takeo 東京大学, 物性研究所, 准教授 (80332956)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: スピントロニクス / スピン軌道相互作用 / スピンポンピング / カーボンナノチューブ / マグノン / 磁気回転効果 / グラフェン

Outline of Final Research Achievements

A microscopic theory of generation and detection of spin current beyond the phenomenological theory was constructed, and research aimed at the discovery of new spin transport phenomena was carried out. We have constructed a microscopic theory of spin injection for a variety of materials and have shown that variations in resonance linewidths provide useful information about spin excitations of adjacent materials. We also constructed a microscopic theory of spin Hall magnetoresistance and succeeded in obtaining a temperature dependence that has not been clarified so far. In parallel, a new nanorotor utilizing electron transport and spin-rotation coupling was proposed. We developed theory of various transport properties using the above theoretical bases.

Free Research Field

物性理論

Academic Significance and Societal Importance of the Research Achievements

強磁性共鳴を利用したスピンポンピング測定がスピン励起のスペクトロスコピー法として有望であるを様々な例を通して示し、今後新しい手法として発展する基盤を構築した。磁性体のスピン状態の読み出し法として注目を集めるスピンホール磁気抵抗であるが、磁気抵抗が何をみているのかを明らかにし、今後のデバイス設計の指針を与えることに成功した。さらにナノローターの提案など、新しい磁気回転効果の応用例も明らかにし、応用の幅を広げることにも貢献した。