能量ε<0时Li原子在平行电磁场中的光吸收谱研究

利用包括实散射的闭合轨道理论和分区自洽的迭代算法,计算了标度能量为ε =- 0 .0 3,标度电场F =0 .0 1时的平行电磁场中n≈ 4 0 ,m =0的Li原子闭合轨道以及光吸收谱.介绍了谱的标度特性 ,它对理解量子与经典之间的对应关系具有非常重要的意义.并与同样情况下的氢原子谱作了比较 .验证了离子实对光吸收过程的重要作用. By employing the semiclassical closed-orbit theory including core-scattering and region-splitting consistent iterative method, we calculate the closed-orbits and the recurrence spectra of n≈40, m=0 Li Rydbergatom in parallel electric and magnetic fields at scaled energy ε=-0.03. The constant scaled electric field is =0.01 . The novel spectral structures are compared with those of hydrogen obtaines by standard closed orbit theory. The effect of the core-scattering has been discussed.     

垂直电磁场中He原子的吸收谱和回归谱的理论计算

半经典闭合轨道理论已经成功地计算了在外加磁场和平行电磁场中的里德堡原子的回归谱.但对于垂直电磁场中的里德堡原子,理论和计算都变得更为复杂.本文把闭合轨道理论推广到三维情况,采用 B.Hüpper的模型势计算了ε=-0.03,主量子数n≈ 40,m=0下He原子在垂直电磁场中的光吸收谱和回归谱,并和H原子在垂直电磁场中的回归谱作比较,突出了实散射的贡献.计算中应用了离子实散射的分区自洽迭代方法,并考虑到轨道的多次重复和离子实的多次散射效应.这是对闭合轨道理论的验证和进一步推广.     

平行电磁场中He+2的回归谱与闭合轨道的研究

利用半经典闭合轨道理论和分区自洽迭代方法计算了Rydberg态下He⁺₂在平行电磁场中的回归谱与闭合轨道. 为了模拟分子实的散射作用,引入一个包含电子交换势的新势能. 利用这一新势能,结合多通道量子亏损和分子闭合轨道理论,讨论了分子实散射效应对平行电磁场中He⁺₂的回归谱与闭合轨道的影响. 关键词： 回归谱 分子半经典闭合轨道 交换势 实散射     

里德堡NO分子在强磁场中的回归谱

利用分子轨道理论,结合一个新的模型势,我们给出了里德堡NO分子中激发态电子所受到的作用势的解析表达式.利用分子的闭合轨道理论和分区自洽的迭代方法,首次从理论上计算了NO分子在强磁场中的回归谱.通过和A.Matzkin等人给出的NO分子在强磁场中的实验谱的比较,表明我们的计算是正确的.     

外电场中Li原子回归谱的分岔效应

半经典闭合轨道在外场和激光参数的某些值附近发生分岔，导致波函数的发散，使原有的半经典闭合轨道理论失效-计算了高激发的Li原子在标度能量为ε=-2-94，标度电场在135 -86-1/4<160-11范围内光吸收谱的Fourier变换，分析了轨道分岔现 象及其影 响，并采用了一种适用于不同能域的统一近似方法修正了分岔点附近波函数-计算中考虑了 原子实多重散射组合回归效应，并把所得回归谱与用标准半经典闭合轨道理论对Li原子及H 原子的计算结果相比较，证明了轨道分岔效应的重要性- 关键词： 分岔 统一近似 半经典闭合轨道理论 回归谱     

氢分子在磁场中回归谱的散射矩阵理论研究

利用散射矩阵理论，结合扩展的半经典闭合轨道理论和多通道量子亏损理论，计算了磁场中高里德堡H2分子的回归谱．该方法使用了两个空间散射矩阵来描述里德堡电子的动力学性质，计算中可以包括所有阶的实散射的作用．回归谱的每一个尖峰对应着一条闭合轨道，新的额外峰是由于弹性散射和非弹性散射所引起的通道内和通道间的轨道组合，进一步证明了体系通道间和通道内的散射具有同等的重要性．     

强场中NO分子回归谱的长程散射矩阵的理论研究

采用半经典散射矩阵方法研究外磁场中高里德伯态双原子分子在能量范围为77010—77050cm^-1的回归谱.通过引进模型势简化强磁场中NO分子的高里德伯电子的势函数,找出其在核转动量子数分别为N=1,3,5的三个通道中的闭合轨道,重点分析了强磁场中NO分子的长程散射矩阵元实部的傅里叶变换谱与闭合轨道之间的一一对应关系.     

氢分子在磁场中回归谱的散射矩阵理论研究

利用散射矩阵理论,结合扩展的半经典闭合轨道理论和多通道量子亏损理论,计算了磁场中高里德堡H2分子的回归谱.该方法使用了两个空间散射矩阵来描述里德堡电子的动力学性质,计算中可以包括所有阶的实散射的作用.回归谱的每一个尖峰对应着一条闭合轨道,新的额外峰是由于弹性散射和非弹性散射所引起的通道内和通道间的轨道组合,进一步证明了体系通道间和通道内的散射具有同等的重要性.     

氢分子在磁场中回归谱的散射矩阵理论研究

利用散射矩阵理论,结合扩展的半经典闭合轨道理论和多通道量子亏损理论,计算了磁场中高里德堡H2分子的回归谱.该方法使用了两个空间散射矩阵来描述里德堡电子的动力学性质,计算中可以包括所有阶的实散射的作用.回归谱的每一个尖峰对应着一条闭合轨道,新的额外峰是由于弹性散射和非弹性散射所引起的通道内和通道间的轨道组合,进一步证明了体系通道间和通道内的散射具有同等的重要性.     

Li里得堡原子在振荡场中的回归谱研究

文中应用扩展的半经典闭合轨道理论计算了Li原子在平行电磁场加一个振荡电场中的回归谱.与相同情况下平行电磁场中的回归谱比较,当附加含时振荡场时,静外场中的吸收光谱的强度被很大程度地减弱.另外,分别讨论了回归谱强度随振荡场振幅以及频率的变化规律.     

Short-ranged potential effects on the recurrence spectra of lithium M = 1 atoms in parallel electric and magnetic fields

This paper presents recurrence spectra of highly excited lithium atoms with M = 1 state in parallel electric and magnetic fields at a fixed scaled energy ε = -0.03. Short-ranged potentials including ionic core potential and centrifugal barrier are taken into account. Their effects on the states and photo-absorption spectrum are analysed in detail. This demonstrates that the geometric features of classical orbits are of special importance for modulations of the spectral pattern. Thus the weak polarization as well as the reduction of correlation of electrons induced by short-ranged potentials give rise to the recurrence spectra of lithium M = 1 atoms more compact than that of the M = 0 one, which is in good agreement with the experimental prediction.     

Recurrence spectra of non—hydrogen Rydberg atoms in paralled electric and magnetic fields

We present a new method for computing the recurrence spectra of n≈40, m=0 lithium Rydberg atoms in strong parallel external electric and magnetic fields. This method is based on an extended closed-orbit theory allowing the computation of the scattering of the electron by the ionic core. We pay particular attention to the scaling properties, which are extremely important for understanding the correspondence between classical and quantum mechanics. The spectra with a constant scaled electric field \tilde F=0.01 and a scaled energy ε=-0.03 are recorded and compared with those of hydrogen obtained by the standard closed-orbit theory. The result shows that the additional strong resonance structures can be interpreted in terms of the core-scattered classical closed orbits.     

The closed-orbit and the photoabsorption spectra of lithium atom in varying＇magnetic fields

Using a simple analytic formula from closed orbit theory, we have calculated the photoabsorption spectra of Li atom in different magnetic fields. Closed orbits in the corresponding classical system have also been obtained for B=5.96T.We demonstrate schematically that the closed orbits disappear gradually with the decrease of the magnitude of the magnetic field. This gives us a good method to control the closed orbits in the corresponding system by changing the magnetic field, and thus changing the peaks in the photoabaorption spectra. By comparing the photoabsorption spectra of Li atom with those of hydrogen case, we find the core-scattered effects play an important role in multi-electron Rydberg atoms.     

Semiclassical calculation of the recurrence spectra of He Rydberg atom in perpendicular electric and magnetic fields

Closed orbit theory is a semiclassical technique for explaining the spectra of Rydberg atoms in external fields. By developing the closed orbit theory from two degrees of freedom to three non-separable degrees of freedom, we calculated the recurrence spectra of He Rydberg atom in perpendicular electric and magnetic fields. The closed orbits in the corresponding classical system have also been obtained. Fourier transformed spectra of He atoms have allowed direct comparison between the resonance peaks and the scaled action values of closed orbits, whereas the nonhydrogenic resonance can be explained in terms of the new orbits created by the core scattering. The semiclassical result is in good agreement with the quantum spectra, which suggests that our method is correct.     

平行电磁场中高里德堡态锂原子自电离的半经典分析

利用Poincaré截面和标度回归谱理论对平行电磁场中高里德堡态锂原子自电离现象进行了半经典分析.并与相同条件下氢原子的相应性质进行比较,结果表明两者有很大不同,这主要是由于离子实散射引起的.从而表明离子实对非氢原子的混沌性质起着非常重要的作用.     

强磁场中Rydberg NO分子的回归谱研究

利用分子的闭合轨道理论和多通道量子亏损理论,考虑核的转动影响,计算了Rydberg NO分子在外磁场中的回归谱.研究表明,复杂谱的结构可以用包含分子实散射的闭合轨道理论来解释,不管是同一通道内的弹性散射还是不同通道间的非弹性散射都起着非常重要的作用,尤其是较大标度作用量下,散射作用远大于基本轨道和重复轨道的贡献,很大程度上影响着体系的动力学性质。     

Semiclassical Calculation of Recurrence Spectra of He Rydberg Atom in Strong External Fields

Using core-scattered closed-orbit theory and region-splitting iterative method, we calculated the scaled recurrence spectra of helium atom in parallel electric and magnetic fields. Closed orbits in the corresponding classical system have also been obtained. When we search the closed orbits, in order to remove the Coulomb singularity of the classical Hamiltonian motion equations, we implement the Kustaanheimo-Stiefel transformation, which transforms the system from a three-dimensional to a four-dimensional one. The Fourier transformed spectrum of helium atom has allowed direct comparison between peaks in such plot and the scaled action values of closed orbits. The results are compared with those of the hydrogen case, which shows that the core-scattered effects play an important role in the recurrence spectra of the multi-electron Rydberg atom.     

Ba Rydberg原子M = 0电场常数标度能谱

选择激光偏振方向，同步改变激发激光的波长(即原子的激发能量E）和外加电场强度 F，使标度能ε=E/F保持为常数，得到了原子束中Ba Rydberg原子在标度 能ε=-300时M=0激发的常数标度能谱.由实验标度能谱的Fourier变换得到的回 归谱与氢的均匀化近似后的闭合轨道理论计算相比较，发现实验回归谱的峰值位置与理论计 算符合较好，而峰值强度则与理论相差较大，分析认为是由于受到核散射和双电子微扰态的 影响所致. 关键词： 标度能谱 闭合轨道理论