| Project/Area Number |
17K14428
|
|---|
| Research Category |
Grant-in-Aid for Young Scientists (B)
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Physical chemistry
|
|---|
| Research Institution | Hokkaido University |
|---|
Principal Investigator |
Iwasa Takeshi 北海道大学, 理学研究院, 助教 (80596685)
|
|---|
| Project Period (FY) |
2017-04-01 – 2020-03-31
|
| Project Status |
Completed (Fiscal Year 2019)
|
| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2019: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2017: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
|
|---|
| Keywords | 近接場光 / 多重極ハミルトニアン / Ehrenfest分子動力学 / 近接場光励起 / 第一原理分子動力学 / 時間依存密度汎関数理論 / 近接場光学 / 理論化学 / 物理化学 / 化学物理 |
|---|
| Outline of Final Research Achievements |
Near field, a highly localized non-uniform light field around a surface, can excite a molecule to dipole-forbidden excited states and can induce unexpected photo chemical reactions. To understand the interactions between the near-field and molecule, a theoretical method beyond the widely used dipole approximation is required. We have developed a theory starting from the original form of the Hamiltonian before the dipole-approximation. The theory is applied to an Ehrenfest molecular dynamics. In addition, we studied structural and electronic properties and relaxation pathways in dipole-forbidden excited states of pure and adsorbed molecules relevant to the near-field excitations. Near-field vibrational excitations including near-field IR and Raman spectroscopic experiments have also been studied by means of an integrated computational chemistry and computational electrodynamics technique. In the future, a diabatic method for near-field photochemistry will be developed.
|
| Academic Significance and Societal Importance of the Research Achievements |
近接場光は伝搬光にはない局在性という特徴を持ち、双極子近似を超えた光学応答や、伝搬光とは異なる光化学反応も報告されている。また伝搬光は回折限界があるため、その空間分解能は波長の半分程度に制限されるが、近接場光ではこのような制限がなくなる。最近は特に走査型プローブ顕微鏡と組み合わせた実験も出てきており、単分子の分子内振動イメージングなどの原子レベルの分解能を持った分光や、単分子の光化学反応の誘起と解析も可能になってきている。近接場光と分子の相互作用から出てくる新しい科学を理解・開拓していくためには、双極子近似を超えた理論化学に基づいた本手法が必要であり、今後も更に発展させていく。
|
