Coherent Control of Atomic Excitation in Strong Fields

我们开发了一种更有效的数值方法来求解强激光场中任意原子的含时薛定谔方程，由于这是研究项目的第一年，我们不仅致力于开发模拟代码，而且还重写了代码，使其能够在最新的模拟加速器--GPU机器上运行。我们还致力于描述成形的激光脉冲或啁啾脉冲，并使用啁啾脉冲来控制原子的动力学过程。所有这些进展保证了我们可以顺利地进行拟议的研究。通过数值模拟，我们发现所得到的束缚态布居对强度和CEP都很敏感。实验数据与理论预测相吻合，实验结果鼓励使用精确定制的激光场来相干地控制强场激发过程。我们发现依赖于CEP的束缚态布居数在低强度和高强度下有着明显不同的行为，边界清晰，我们将其归因于从多光子到隧道机制的转变。这项研究已经发表在《物理评论快报》上。这项工作使我们在这一研究领域处于领先地位。我们还与电子通信大学的一个实验小组合作，揭示了导致类铍高电荷离子意外大极化的物理机制。这项研究也发表在《物理评论快报》上。

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.