| Project/Area Number |
16H03876
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Optical engineering, Photon science
|
|---|
| Research Institution | Hokkaido University |
|---|
Principal Investigator |
TODA YASUNORI 北海道大学, 工学研究院, 教授 (00313106)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
土屋 聡 北海道大学, 工学研究院, 助教 (80597633)
|
|---|
| Project Period (FY) |
2016-04-01 – 2019-03-31
|
| Project Status |
Completed (Fiscal Year 2018)
|
| Budget Amount *help |
¥15,600,000 (Direct Cost: ¥12,000,000、Indirect Cost: ¥3,600,000)
Fiscal Year 2018: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
Fiscal Year 2017: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
Fiscal Year 2016: ¥9,100,000 (Direct Cost: ¥7,000,000、Indirect Cost: ¥2,100,000)
|
|---|
| Keywords | 光物性 / 高温超伝導 / 時間分解分光 / 応用光学・量子光工学 / 特異点光学 / 軌道角運動量 / 光渦 / 軌道角運動 / 自発的対称性破れ |
|---|
| Outline of Final Research Achievements |
Using ultrafast optical vortex pulses, we have demonstrated the observation of the orbital angular momentum (OAM) dynamics of carriers for high-Tc superconductors (Bi2212) and obtained the following results: (a) OAM-dependent transient reflectivity changes are observed below Tc, indicating that the optical vortex can transfer its OAM to the superconducting state (quasi-particles and/or cooper-pairs); (b) recovery dynamics of the superconducting state shows an efficient contribution of the pairing fluctuation in its early stage; (c) temperature dependence of the OAM dynamics shows virtually no pairing fluctuation, suggesting that the optical vortex induced OAM dynamics reflects a spatially coherent dynamics associated with a global quantum correlation.
|
| Academic Significance and Societal Importance of the Research Achievements |
らせん状の波面で特徴づけられる光渦は（偏光とは独立に）ビーム断面内にエネルギー流の方位回転成分を持ち、物質に照射すると大域的な電子の軌道角運動を励起できる。本研究ではこの光渦を超伝導の時間分解分光に対して活用することにより、従来の分光では測定が困難だった電子同士の大域的な相関ダイナミクスの観測を実現した。高温超伝導体では電子相関がクーパー対形成に対して重要な役割を果たすと考えられるため、確立された測定手法は超伝導の発現機構解明に新しい知見をもたらすと共に、巨視的相関にもとづくユニークな超伝導相制御の創出につながる。
|
