Understand and control the ionization processes of atoms and molecules in strong two-color laser fields

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K05495
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Atomic/Molecular/Quantum electronics
• Research Institution: University of Tsukuba
• Principal Investigator: Tong XiaoMin 筑波大学, 計算科学研究センター, 准教授 (80422210)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 強レーザー場 / 原子励起と電離 / アト秒物理 / 楕円偏光

Outline of Final Research Achievements

We have developed a new time-dependent density functional method based on FFT for atoms, molecules, clusters and nano-particles in a strong laser field. Based on the method, we have investigated the ionization and dissociation processes of hydrogen molecules, oxygen molecules in an intense laser field and based the understanding we proposed a way to control the dynamics processes by intense lasers. Meanwhile, to cope with the researches on the generating a circularly polarized attosecond pulse, we have investigated the related processes, atomic ionization in two-color circularly polarized laser fields and our results are in good agreement with experiments. Specially, we have developed a theory to treat the photo-ionization and photo-excitation of atoms in a strong elliptically polarized field in a unified way and the method can be used for many dynamics processes.

Free Research Field

物理　原子分子

Academic Significance and Societal Importance of the Research Achievements

本研究は基礎研究である。学術意義について三の点から述べる。（１）計算方法の開発：より精度の良い時間依存密度汎関数の計算方法を開発し、強レーザーにおけるナノ粒子の動的過程を理論計算で調べることができる。（２）基礎過程の解明：理論計算で、強レーザー場の補助で水素分子や酸素分子X線での電離と解離のメカニズムを解明し、基礎の過程に対して、理解できる。（３）動的過程の制御：メカニズムの解明による、レーザーの強度やX―線との到着の時間遅延で電離と解離過程の制御ができることを明らかになった。