Study on the relaxation mechanism of valley polarization in atomically-thin transition metal dichalcogenides
| Project/Area Number |
17K19055
|
|---|
| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Applied condensed matter physics and related fields
|
|---|
| Research Institution | Kyoto University |
|---|
Principal Investigator |
MIYAUCHI Yuhei 京都大学, エネルギー理工学研究所, 准教授 (10451791)
|
|---|
| Project Period (FY) |
2017-06-30 – 2020-03-31
|
| Project Status |
Completed (Fiscal Year 2019)
|
| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000)
Fiscal Year 2018: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2017: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
|
|---|
| Keywords | 遷移金属ダイカルコゲナイド / バレー / 励起子 / 原子層 / 半導体 / バレートロニクス / バレー緩和 |
|---|
| Outline of Final Research Achievements |
We studied the relaxation mechanism of exciton valley polarization in a single layer of tungsten diselenide WSe2, one of the typical transition metal dichalcogenide layered semiconductors. We found that the exciton valley relaxation observed in the experiments can be comprehensively understood, predicted, and controlled by taking into account the coupling between the two valley states through electron-hole exchange interactions with the screening effect by the doped carriers. We have also developed a new method to predict the valley polarization at low temperatures with high accuracy based on the characteristics of the emission spectra at room temperature using a machine learning algorism.
|
| Academic Significance and Societal Importance of the Research Achievements |
本研究では、代表的な遷移金属ダイカルコゲナイドWSe2の単層膜をモデルケースとして、円偏光によって生成された励起子のバレー分極情報が失われる機構を突き止めた。さらに、機構の理解に基づいて材料に工夫を施すことで、バレー状態をより長く保つことができることを見出した。本研究の成果は、２次元原子層半導体の基礎的かつ重要な光物性の１つが明らかになったという意義に加え、バレー自由度を情報キャリアとして用いる将来の高速・省エネルギー光情報デバイス実現に向けた材料設計の工学的指針を与えるものである。
|
Report
(4 results)
Research Products
(46 results)
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
[Journal Article] Evidence for line width and carrier screening effects on excitonic valley relaxation in 2D semiconductors2018
Author(s)
Y. Miyauchi, S. Konabe, F. Wang, W. Zhang, A. Hwang, Y. Hasegawa, L. Zhou, S. Mouri, M. Toh, G. Eda, K. Matsuda
-
Journal Title
Nature Communications
Volume: 9
Issue: 1
Pages: 2598-2598
DOI
NAID
Related Report
Peer Reviewed / Open Access / Int'l Joint Research
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
