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51.
第十届全国原子与分子物理学术会议于2000年8月6日至11日在山东省济南市召开.会议由中国物理学会原子与分子物理专业委员会主办,山东师范大学承办.山东师范大学副校长张庆刚教授担任会议主席,山东师范大学物理系主任仝殿民教授担任组织委员会主任.本届会议是世纪之交原子分子物理学界的一次学术盛会.来自全国各地几十所著名高等学府和专业科研院所的86名专家、学者出席会议.我国原子与分子物理学科奠基人、著名物理学家、四川大学原子分子物理研究所的八十三岁高龄的清泉教授亲自到会并作大会报告.参加本次大会的还有中国物理学会原子与分… 相似文献
52.
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. 相似文献
53.
An expansion method for stationary states is applied to obtain the eigenfunctions and the eigenenergies of the quarter stadium billiard, and its nearest energy-level spacing distribution is obtained. The histogram is consistent with the standard Wigner distribution, which indicates that the stadium billiard system is chaotic. Particular attention is paid to pursuing the quantum manifestations of such classical chaos. The correspondences between the Fourier transformation of quantum spectra and classical orbits are investigated by using the closed-orbit theory. The analytical and numerical results are in agreement with the required resolution, which corroborates that the semiclassical method provides a physically meaningful image to understand such chaotic systems. 相似文献
54.
The formulas of the quantum electrodynamics have been applied to calculate the spontaneous emission rate of excited atom in dielectric microcavity.The results exhibit damping oscillating patterns which depend sensitively on the scaling parameter and geometrical structure.Compared with the case that the emitting atom is immersed in dielectric,the spontaneous emission rate is depressed obviously and the center or the mean value of the oscillations is intimately related to the real refractive index of the local position where the atom is.In order to explain this phenomenon,we utilize the closed-orbit theory to deal with the classical trajectories of the emitted photon,and extract the corresponding frequencies of the oscillations by Fourier transform.It is found that the oscillations can be represented in terms of the closed-orbits of the photon motion constrained in dielectric microcavity,thus providing another perspective on the spontaneous emission of atom sandwiched by dielectric slabs. 相似文献
55.
给出了H-在任意夹角的强电场和磁场中光剥离截面的量子解约化到闭合轨道解的形式,并将其计算结果与量子解的结果进行了比较. 相似文献
56.
Based on the extended closed-orbit theory together with spectral
analysis, this paper studies the correspondence between quantum
mechanics and the classical counterpart in a two-dimensional annular
billiard. The results demonstrate that the Fourier-transformed
quantum spectra are in very good accordance with the lengths of the classical
ballistic trajectories, whereas spectral strength is
intimately associated with the shapes of possible open orbits
connecting arbitrary two points in the annular cavity. This approach
facilitates an intuitive understanding of basic quantum features
such as quantum interference, locations of the wavefunctions, and
allows quantitative calculations in the range of high energies,
where full quantum calculations may become impractical in general.
This treatment provides a thread to explore the properties of
microjunction transport and even quantum chaos under the much more
general system. 相似文献
57.
A semiclassical method based on the closed-orbit theory is applied to
analysing the dynamics of photodetached electron of H$^- $ in the
parallel electric and magnetic fields. By simply varying the magnetic
field we reveal spatial bifurcations of electron orbits at a fixed
emission energy, which is referred to as the fold caustic in
classical motion. The quantum manifestations of these singularities
display a series of intermittent divergences in electronic flux
distributions. We introduce semiclassical uniform approximation to
repair the electron wavefunctions locally in a mixed phase space and
obtain reasonable results. The approximation provides a better
treatment of the problem. 相似文献
58.
This paper presents theoretical computations of the ionization rate of Rydberg lithium atom above the classical ionization threshold using semiclassical approximation. The yielded random pulse trains of the escape electrons are recorded as a function of emission time such that they can be related to the terms of the recurrence periods of the photoabsorption. This fact illustrates that it is ionic core scattering processes which give rise to chaos in autoionization dynamics and this is verified by comparison of our results with the hydrogen atom situation. In order to reveal the chaotic properties in detail, the sensitive dependence of the ionization rate upon the scaled energy is discussed for different scaled energies. This approach provides a simple explanation for the chaotic character in autoionization decay of Rydberg alkali-metal atoms. 相似文献
59.
Correspondence between classical dynamics and recurrence spectra of Rydberg hydrogen atom near a metal surface
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The chaotic behaviours of the Rydberg hydrogen atom near a metal surface are presented. A numerical comparison of Poincare surfaces of section with recurrence spectra for a few selected scaled energies indicates the correspondence between classical motion and quantum properties of an excited electron. Both results demonstrate that the scaled energy dominates sensitively the dynamical properties of system. There exists a critical scaled energy εc, for ε 〈 εc, the system is near-integrable, and as the decrease of ε the spectrum is gradually rendered regular and finally turns into a pure Coulomb field situation. On the contrary, if ε 〉 εc, with the increase of ε, the system tends to be non-integrable, the ergodic motion in phase space presages that chaotic motion appears, and more and more electrons are adsorbed on the metal surface, thus the spectrum becomes gradually simple. 相似文献
60.
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. 相似文献