Quantum simulation for many-electron dynamics induced by light

我们利用基于时变密度泛函理论的第一性原理计算方法研究了光与物质之间的相互作用。我们在多电子动力学的量子模拟研究方面取得了进展，在实时和实空间中求解时变的Kohn-Sham方程。本研究的主要结果之一是强激光场与原子和分子的相互作用。我们首次实现了原子和分子隧道电离速率的第一性原理计算，获得了HOMO轨道性质的意义、极化效应对电离速率的影响等有关电离机理的重要知识。我们还实现了高谐波产生的三维计算，并研究了分子取向和筛选的影响。在紫外区光吸收的计算上也取得了一些进展。分子的振荡强度分布一般集中在电离阈值以上的能区，反映了分子的几何形状。除了小分子外，对该区域振荡强度的理论研究还没有取得很大进展。我们用连续体耦合的时间依赖密度函数方法计算了C3H6同分异构体的振荡强度分布，并证明了不同异构体的紫外光谱差异在我们的计算中得到了准确的再现。我们的多电子动力学的实时空间计算方法最初是在核理论中发展起来的。原子核理论和电子理论有一个共同的方面，因为它们都是凝聚态费米子系统。我们将本研究中发展的理论框架应用于核多体动力学。特别地，我们发展了具有吸收势的散射现象的描述，并研究了原子核的分裂反应和连续光学响应。少

We have developed a study on interactions between light and matter with the first-principle computational method based on the time-dependent density functional theory. We have made a progress on the quantum simulation study for many-electron dynamics in which the time-dependent Kohn-Sham equation is solved in real-time and real-space.One of the mail results of the present study is concerning the interaction of intense laser field with atoms and molecules. We have achieved a first-principle calculation of the tunnel ionization rate of atoms and molecules for the first time, and obtained important knowledge about the ionization mechanims such as the significance of the HOMO orbital properties and the polarization effect on the ionization rate. We have also achieved a three-dimensional computation of high-harmonic generation and have investigated the effects of molecular orientation and screening.We have also made a progress on the computation of the optical absorption in the ultraviolet … More region. The oscillator strength distribution of molecules is, in general, concentrated in the energy region above the ionization threshold and reflects the geometry of the molecule. A theoretical study of oscillator strength in that region have not been achieved much except for small molecules. We have achieved calculations of the oscillator strength distribution for C3H6 isomers in the time-dependent density functional method with continuum coupling, and have demonstrated that the difference of the UV spectra between isomers is accurately reproduced in our calculation.Our real-space and real-time computational method for the many-electron dynamics was originally developed in the nuclear theory. The nuclear and electronic theories has a common aspect since they both are condensed fermion systems. We have applied theoretical frameworks developed in the present study to nuclear many-body dynamics. In particular, we have developed a description of scattering phenomena with the absorbing potential, and have studies breakup reactions and the continuum optical responses of nuclei. Less