Photoelectron spin interference studied for the basic theory of spin- and angle-resolved photoemission spectroscopy

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K03484
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13020:Semiconductors, optical properties of condensed matter and atomic physics-related
• Research Institution: National Institute for Materials Science (2020); The University of Tokyo (2018-2019)
• Principal Investigator: YAJI Koichiro 国立研究開発法人物質・材料研究機構, 先端材料解析研究拠点, グループリーダー (50447447)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: スピン軌道結合 / スピン干渉 / スピン角度分解光電子分光

Outline of Final Research Achievements

Spin- and angle-resolved photoemission spectroscopy (SARPES) is a powerful technique to to investigate strongly spin-orbit coupled electronic states. However, the correspondence between the spin structure in the initial state and that in the photoexcited state is not obvious since SARPES provides the information of photoelectrons that can be changed with the matrix element effect of photoemission. In the present study, we have elucidated the spin interference in the photoemission process with mirror symmetry. We have developed a basic theory to obtain the spin information in the initial state from the spin structure of photoelectrons observed with SARPES.

Free Research Field

光物性

Academic Significance and Societal Importance of the Research Achievements

トポロジカル物質などの強いスピン軌道相互作用が重要な電子スピン物性分野の登場により、スピン角度分解光電子分光は電子状態測定手法として広く使われるようになった。しかしながら、そのデータ解釈の方法については曖昧にされたままあった。本研究では、同手法の基礎学理を構築し、電子スピン物性に関する物理を大きく進展させることに貢献した。また本研究で得られた成果は、光励起過程における位相の自由度も利用してスピンを制御できるという新たな概念となり、例えばスピン偏極電子源の開発に応用できる。