High-harmonic coherent responses from semiconductor nanocrystals
| Project/Area Number |
18K13481
|
|---|
| Research Category |
Grant-in-Aid for Early-Career Scientists
|
| Allocation Type | Multi-year Fund |
|---|
| Review Section |
Basic Section 13020:Semiconductors, optical properties of condensed matter and atomic physics-related
|
|---|
| Research Institution | Kyoto University |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2018-04-01 – 2020-03-31
|
| Project Status |
Completed (Fiscal Year 2019)
|
| Budget Amount *help |
¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2019: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2018: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
|
|---|
| Keywords | 光物性 / エキシトン / マルチエキシトン / ナノ粒子 / ナノフォトニクス / コヒーレント制御 |
|---|
| Outline of Final Research Achievements |
In this study, we investigated the mechanism of harmonic coherent response of electrons in semiconductor nanocrystals. We developed a method to directly measure coherent response of excitons by using a phase-locked optical pulse pair, where the relative phase of two pulses are stabilized with high precision. We successfully observed higher-order dipole oscillations via the formation of multiexcitons under the resonant excitation of the lowest exciton level of nanocrystals. Furthermore, we clarified that the absorption energy shift is caused by the generation of hot excitons possessing high excess energies. These results provide direct evidence that multiexcitons and hot excitons play critical roles in optical responses of semiconductor nanocrystals.
|
| Academic Significance and Societal Importance of the Research Achievements |
半導体ナノ粒子は、電子の量子閉じ込め効果を利用することで光学的・電気的に特異な性質を示す材料として注目されている。本研究では、この半導体ナノ粒子中に光で生成した電子状態について、高い振動数を持った応答である高調波コヒーレンスが生じることを明らかにした。入射した光の周波数よりも高い周波数を持った電子応答が半導体ナノ粒子中で生じることを明らかにした本研究は、半導体ナノ粒子の光学応答の理解を深めるとともに、新しい光エネルギーの利用法や新規光源技術につながる成果である。特に、本研究で扱った半導体ナノ粒子は赤外に光吸収領域を持つため、赤外光の有効利用につながると期待できる。
|
Report
(3 results)
Research Products
(16 results)
