双平行金属板间的里德堡氢原子的动力学性质

用相空间分析方法研究了双金属板间里德堡氢原子的动力学性质.结果表明：标度变换后,其动力学行为敏感地依赖于标度能量 .当标度能量 较小时,体系是近可积的,规则的,随着标度能量的增大,体系是不可积的,运动是混沌的,电子可能被金属表面俘获.     

外电场中金属表面附近里德堡氢原子的动力学行为

利用相空间分析方法研究了外电场中金属表面附近里德堡氢原子的动力学性质. 结果表明, 体系的动力学性质敏感地依赖于原子与金属表面间的距离和电场强度.通过固定原子与金属表面间的距离, 分析了外加电场作用下里德堡电子的Poincaré 截面和运动轨迹的演化过程. 研究表明: 电场的出现加速了金属表面对电子的吸附, 随着电场强度的增加,体系的动力学性质由原子与金 属表面间的距离控制逐渐变为由电场起主导作用,体系逐渐由不可积变为可积, 电子的运动轨道最终全部变为振动型轨道. 关键词： Poincaré截面 相空间分析方法 里德堡氢原子     

高里德堡态氢原子与氦原子散射的高分辨研究

利用了氢原子飞渡时间谱实验方法对处于高n主量子数里德堡态的氢原子与氦原子的分子束散射过程进行了高分辨研究.测量了H(n)+He→H(n′)+He散射过程的散射微分截面.实验结果表明,产物主要分布在前向散射方向,在侧向也有一定的分布.在前向和侧向存在大量的振荡结构.同时详细的研究也表明,在上述的散射过程中往前散射的方向上,氢原子里德堡态主量子数n的变化并不是很大.实验结果得到了为理论上精确研究高n主量子数里德堡态的氢原子与氦原子的散射动力学的一套精细的实验数据.     

氢原子光谱实验中里德堡常数的估计方法探讨

考察了氢原子光谱实验中估计里德堡常数的三种可能方法。我们的分析表明：由于标准差较大,且标准差不会随测量的谱线数趋于无穷而趋于零,采用所谓的斜率估计法是不太妥当的。虽然采用所谓截距估计法会使标准差大大减少,而且,标准差会随所测量的谱线数趋于无穷而趋于零。但RH的最佳估计值应该以波数为纵坐标y,（1／2^2—1／m^2）为横坐标x,作y=kx形式的拟合得到。     

磁场中氢里德堡波包的自动关联函数

本文采用激光短脉冲激发磁场中氢原子,研究氢里德堡波包在磁场中随时间的演化.结果证实氢里德堡波包在磁场中的运动也与闭合轨道密切相关.讨论了脉冲宽度τ对自动关联函数的影响以及不同初始态下的自动关联函数.     

镁原子里德堡能级的计算

依据最弱受约束电子势模型理论,计算了镁原子1s22s22p63snp 3P2,1,0(n=3～50) 和1s22s22p63sns 3S1 (n=4～50)里德堡系列的能级和量子亏损. 计算结果与已有的33个实验数据符合得很好,预言了136个能级的位置.     

镁原子里德堡能级的计算

依据最弱受约束电子势模型理论，计算了镁原子1s22s22p63snp 3P2,1,0(n=3-50) 和1s22s22p63sns 3S1 (n=４-50)里德堡系列能级和量子亏损。计算结果与已有的33个实验数据符合得很好，预言了136个能级的位置。     

碳原子里德堡能级的计算

依据最弱受约束电子势模型及其微扰修正理论,计算了碳原子1s22s22pns 3P02,1,0 (n=3-50) 和1s22s22pnd 3F03,2 (n=3-50)里德堡系列能级和量子亏损。计算结果与已有的实验结果符合得很好。     

氢里德堡原子在磁场中的双脉冲谱

考虑完全相同的两束激光脉冲与原子相互作用的过程,研究氢里德堡波包在磁场中随时间的演化.结果显示了波包的运动与闭合轨道密切相关.讨论了双脉冲的相位参数以及脉冲宽度对谱的影响.     

Resonances of a hydrogen atom in strong parallel electric and magnetic fields using B-spline basis sets

The B-spline basis set plus complex scaling method is applied to the numerical calculation of the exact resonance parameters $E_r}$ and $\Ga/2$ of a hydrogen atom in parallel electric and magnetic fields. The method can calculate the ground and higher excited resonances accurately and efficiently. The resonance parameters with accuracies of $10^{-9}-10^{-12}$ for hydrogen atom in parallel fields with different field strengths and symmetries are presented and compared with previous ones. Extension to the calculation of Rydberg atom in crossed electric and magnetic fields and of atomic double excited states in external electric fields is discussed.     

Resonances of a hydrogen atom in strong parallel electric and magnetic fields using B-spline basis sets

The B-spline basis set plus complex scaling method is applied to the numerical calculation of the exact resonance parameters Er and Г/2 of a hydrogen atom in parallel electric and magnetic fields. The method can calculate the ground and higher excited resonances accurately and efficiently. The resonance parameters with accuracies of 10^-9 - 10^-12 for hydrogen atom in parallel fields with different field strengths and symmetries are presented and compared with previous ones. Extension to the calculation of Rydberg atom in crossed electric and magnetic fields and of atomic double excited states in external electric fields is discussed.     

平行电磁场中的Rydberg锂原子吸收谱的模型势计算

用B样条基组展开方法结合模型势计算了Rydberg锂原子在平行电磁场下的振子强度谱. 径向和角向均采用高阶Ｂ样条基组.计算结果与已有的实验结果符合得很好.利用分波分析法,对部分谱线的振子强度的强弱进行了分析. 本文方法简单有效，易于推广到交叉电磁场中Rydberg原子的精确谱的计算. 关键词： B样条 能谱 振子强度 平行电磁场 Rydberg原子     

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.     

The dynamical properties of Rydberg hydrogen atom near a metal surface

In recent years much attention is focused on the dynamics of Rydberg atom in exter- nal fields. At the same time Rydberg atom near a metal surface plays an important role as a typical theoretical model and produces measurable experimental response[1]. As an interesting model it covers many dynamical effects: instantaneous van der Waals inter- action[2,3], Zeeman-Stark effects and diamagnetic effects in strong fields[4], and so on. Its classical motion is very complex. When the atom-surface i…     

The dynamical properties of Rydberg hydrogen atom near a metal surface

The dynamical properties of Rydberg hydrogen atom near a metal surface are presented by using the methods of phase space analysis and closed orbit theory. Transforming the coordinates of the Hamiltonian, we find that the phase space of the system is divided into vibrational and rotational region. Both the Poincaré surface of section and the closed orbit theory verify the same conclusion clearly. In this paper we choose the atomic principal quantum number asn=20. The dynamical character of the exited hydrogen atom depends sensitively on the atom-surface distanced. Whend is sufficiently large, the atom-surface potential can be expressed by the traditional van der Waals force and the system is integrable. Whend becomes smaller, there exists a critical valued _c. Ford>d _c, the system is near-integrable and the motion is regular. While chaotic motion appears ford<d _c, and the system tends to be non-integrable. The trajectories become unstable and the electron might be captured onto the metal surface.     

Fractal dynamics in the ionization of helium Rydberg atoms

We study the ionization of helium Rydberg atoms in an electric field above the classical ionization threshold within the semiclassical theory.By introducing a fractal approach to describe the chaotic dynamical behavior of the ionization,we identify the fractal self-similarity structure of the escape time versus the distribution of the initial launch angles of electrons,and find that the self-similarity region shifts toward larger initial launch angles with a decrease in the scaled energy.We connect the fractal structure of the escape time plot to the escape dynamics of ionized electrons.Of particular note is that the fractal dimensions are sensitively controlled by the scaled energy and magnetic field,and exhibit excellent agreement with the chaotic extent of the ionization systems for both helium and hydrogen Rydberg atoms.It is shown that,besides the electric and magnetic fields,core scattering is a primary factor in the fractal dynamics.     

Chaos in the hydrogen atom interacting with external fields

In this review we discuss the chaotic dynamics (both classical and quantal aspects) of a simple atomic system, namely hydrogen atom interacting with time independent and time dependent external fields. These include: i) static electric field, ii) static magnetic field, iii) combined electric and magnetic fields, in parallel and perpendicular configuration, iv) instantaneous and generalized van der Waals field, v) mass anisotropy and vi) linearly and circularly polarized microwave fields.     

Photoionization microscopy of Rydberg hydrogen atom near a dielectric surface

Based on the semiclassical analysis of photoionization microscopy, we study the ionization of the Rydberg hydrogen atom near a dielectric surface. The radial electron probability density distributions on a given detector plane are calculated at different scaled energies and near different dielectric surfaces. We find due to the interference effect of different types of electron trajectories arriving at a given point on the detector plane, oscillatory structures appear in the electron probability density distributions. With the increase in the scaled energy, more types of electron ionization trajectories appear and the oscillatory structure in the electron probability density distributions becomes complex. Besides, the dielectric constant of the dielectric surface can also affect the electron probability density distributions. Since the photoionization microscopy interference pattern recorded on the detector plane reflects the distribution of the square modulus of the transverse component of the electronic wave function, with the recorded interference pattern, we can investigate the ionization dynamics of the Rydberg atom near surfaces clearly. This study provides some reference values for the future experiment research on the photoionization microscopy of the Rydberg atom near dielectric surfaces.