Development and application of valley-spin photonics in atomically thin layered materials

2020 Fiscal Year Final Research Report

• Project/Area Number: 16H06331
• Research Category: Grant-in-Aid for Scientific Research (S)
• Allocation Type: Single-year Grants
• Research Field: Applied materials
• Research Institution: Kyoto University
• Principal Investigator: Matsuda Kazunari 京都大学, エネルギー理工学研究所, 教授 (40311435)
• Co-Investigator(Kenkyū-buntansha): 小鍋 哲 法政大学, 生命科学部, 准教授 (40535506) ; 北浦 良 名古屋大学, 理学研究科, 准教授 (50394903) ; 岡田 晋 筑波大学, 数理物質系, 教授 (70302388)
• Project Period (FY): 2016-05-31 – 2021-03-31
• Keywords: 原子層物質 / バレースピン / フォトニクス

Outline of Final Research Achievements

We were studying the physics of valley-spin degree of freedom via characteristics quantum optical phenomena in the new platform of atomically thin materials with valley-spin locking systems, and extending these findings to realize the control of valley-spin polarization in this project. The mechanism of relaxation process of exciton valley-spin polarization has been revealed, which is the essential issues in the valley-spin physics. We also realized the continuous external control of valley-spin polarization by applying the bias gate voltage mediated by screening of Coulomb interaction. Moreover, the extremely low threshold light amplification due to the strong light confinement and high luminescence efficiency has been demonstrated in the micro-cavity device structures. Then, we have succeeded to open the new research area of “valley-spin photonics in the atomically thin materials”, which will be contributed to the development of optical and material science research fields.

Free Research Field

工学（応用物性）

Academic Significance and Societal Importance of the Research Achievements

一連の研究は、新たな物理自由度であるバレースピンの本質を明らかにする、という共通の目標に対して、結晶成長・光学実験・第一原理計算・多体理論のエキスパートが連携し共同で遂行することで可能となったものであり、その学術的な意義は物理のみに留まらず広く光科学・物質科学の発展に大きく寄与するものである。さらに、バレースピン制御を利用した新たな原理のデバイスを通して、「バレースピンフォトニクス」という、工学的にも一つの大きな進展があったと言える。