| 研究課題/領域番号 |
22K03493
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| 研究種目 |
基盤研究(C)
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| 配分区分 | 基金 |
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| 応募区分 | 一般 |
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| 審査区分 |
小区分13020:半導体、光物性および原子物理関連
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| 研究機関 | 筑波大学 |
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研究代表者 |
トン ショウミン 筑波大学, 計算科学研究センター, 准教授 (80422210)
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| 研究期間 (年度) |
2022-04-01 – 2026-03-31
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| 研究課題ステータス |
交付 (2022年度)
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| 配分額 *注記 |
4,160千円 (直接経費: 3,200千円、間接経費: 960千円)
2025年度: 520千円 (直接経費: 400千円、間接経費: 120千円)
2024年度: 390千円 (直接経費: 300千円、間接経費: 90千円)
2023年度: 520千円 (直接経費: 400千円、間接経費: 120千円)
2022年度: 2,730千円 (直接経費: 2,100千円、間接経費: 630千円)
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| キーワード | Atomic excitation / Intense laser / elliptical polarization / highly charged ions / Elliptical polarization |
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| 研究開始時の研究の概要 |
Different from atomic ionization, atomic excitation depends on more details of the atomic structure, like our fingerprint and it must be studied case by case or element by element. Such an understanding may result in a new development on steering coherent excited states by tuning the relative phase of the light source, the time-delay between the pump and probe lasers. Most of the excited states will be de-excited to a metastable gas phase, which can be used for atom trap trace analysis.
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| 研究実績の概要 |
We developed a more effective numerical method to solve the time-dependent Schrodinger equation for arbitrary atoms in an intense laser field.
Since this was the first year of the research project, we focus on not only developing the simulation code, but also rewriting the code so it runs on the newest simulation accelerator, a GPU machine. We also worked on describing a shaped laser pulse or chirp pulse and using a chirped pulse to control atomic dynamical processes. All those progress guarantees that we can perform the proposed research smoothly. Through numerical simulations, we show that the resulting bound-state population is sensitive to both the intensity and the CEP. The experimental data agree with the theoretical prediction, and the results encourage the use of precisely tailored laser fields to coherently control the strong-field excitation process. We find a markedly different behavior for the CEP-dependent bound-state population at low and high intensities with a clear boundary, which we attribute to the transition from the multiphoton to the tunneling regime. This work has been published in Physical Review Letters. This work puts us in a leading position in this research field.
We also collaborated with an experimental group at the University of Electro-Communications to uncover the physical mechanisms which lead to an unexpectedly large polarization of Be-like highly charged ions. This work was also published in Physical Review Letters.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
In the proposal, in the first year, we planned to develop and test the proposed method on a local high-performance workstation with the same architecture as the Cygnus supercomputer. This part has been finished and tested on our local single-node GPU workstation. We also proposed to study the difference between the multiphoton and tunneling processes for atomic excitation in a linearly polarized field using the existing code. This work is the continuation of our collaboration with the experiment group at Griffith University. And the joint work has been published in Physical Review Letters. Of course, we have the necessary research experience and the most simulation tools. Another reason to is that we collaborate with several leading research groups internationally. Therefore, we have the research experience and can access the most recent developments in the field.
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| 今後の研究の推進方策 |
With the newly developed code, we will study the strong field excitation of atoms in a chirped pulse. The main focuses are (1) to study a state-specified excitation in a strong field; (2) to control the atomic photon excitation by tuning the laser pulse shape. Apart from this main research direction, we also work on the hyper-satellite structure of electric x-rays emitted from muonic atomic ions to collaborate with the experimental group in RIKEN and the fundamental interactions in highly charged ions to work with the experimental group in the University of Electro-Communications.
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