共查询到20条相似文献,搜索用时 343 毫秒
1.
We develop the semi-closed orbit theory from two degrees of freedom to three non-separable degrees of freedom and put forward a new model potential for the Li Rydberg atom, which reduces the study of the system to an effective one-particle problem. Using this model potential and the closed orbit theory for three degrees of freedom, we calculate the recurrence spectra of Li Rydberg atom in perpendicular electric and magnetic fields. The closed orbits in the corresponding classical system have also been obtained. The Fourier transformed spectra of Li atom 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. Our result is in good agreement with the quantum spectra, which suggests that our calculation is correct. 相似文献
2.
Semiclassical calculation of the recurrence spectra of He Rydberg atom in perpendicular electric and magnetic fields
下载免费PDF全文
![点击此处可从《中国物理》网站下载免费的PDF全文](/ch/ext_images/free.gif)
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. 相似文献
3.
Recurrence spectra of Li atom in strong external fields 总被引:1,自引:1,他引:0
Based upon our previous work [Commun. Theor. Phys.. 40,702 (2003)], we developed the closed orbit theory from two degrees of freedom to three non-separable degrees of freedom and calculated the recurrence spectra of Li Rydberg atom in strong perpendicular electric and magnetic fields. The Fourier transformed spectra of Li atom has 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 one, which suggests that our calculation is correct. 相似文献
4.
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. 相似文献
5.
The closed-orbit and the photoabsorption spectra of lithium atom in varying'magnetic fields
下载免费PDF全文
![点击此处可从《中国物理》网站下载免费的PDF全文](/ch/ext_images/free.gif)
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. 相似文献
6.
WANG De-Hua 《理论物理通讯》2008,49(2):467-472
Multielectron to theoretical treatments atoms near a metal surface are essentially more complicated than hydrogen atom with regard By using the semicalssical dosed orbit theory generalized to the multielecton atoms, we study the dynamical properties of the Rydberg lithium atom near a metal surface. The photoabsorption spectra and recurrence spectra of this system have also been calculated. Considering the effect of the ionic core potential of the Rydberg lithium atom, the number of the closed orbits increases, which leads to more peaks in the recurrence spectra than the case of hydrogen atom near a metal surface. This result shows that the core-scattered effects play an important role in nonhydrogenic atoms. This study is a new application of the closed-orbit theory and is of potential experimental interest. 相似文献
7.
The closed-orbit and the photoabsorption spectra of the Rydberg hydrogen atom between two parallel metallic surfaces
下载免费PDF全文
![点击此处可从《中国物理》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Using the closed orbit theory, we study the classical motion and calculate the
photoabsorption spectra of Rydberg hydrogen atom between two parallel metallic
surfaces. The results show that the metallic surfaces have a significant effect
on the photoabsorption process. When the distances between the hydrogen atom
and the two metallic surfaces are close to a critical value dc, the number
of the closed orbits is the greatest. When the distance larger or smaller
than dc, the number of the closed orbits decreases and the absorption
spectra are shown to exhibit a damping oscillation. This work is an
interesting new application of closed-orbit theory and is of potential
experimental interest. 相似文献
8.
9.
WANG De-Hua LIN Sheng-Lu 《理论物理通讯》2004,42(11)
Using core-scattered closed-orbit theory, we calculate the photoabsorption and the scaled recurrence spectra of sodium Rydberg atom in strong magnetic field below ionization threshold. The non-Coulombic nature of the ionic core have been modified by a model potential, which includes an attractive Coulomb potential and a short-ranged core potential. A family of core-scattered nonhydrogenic closed orbits have also been discovered. The Fourier transformed spectra of sodium atom have allowed direct comparison between peaks in such plot and the scaled action values of closed orbits. The new peaks in the recurrence spectra of sodium atom have been considered as effects caused by the core scattering of returning waves at the ionic core. The results are compared with those of hydrogen case, which show that the core-scattered effects play an important role in alkali-metal atoms. 相似文献
10.
Semiclassical calculation of Rydberg He2^+ molecular of recurrence spectra ion in a magnetic field
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Making use of the molecular closed-orbit theory and a new model potential for the Rydberg molecule, we have calculated the recurrence spectra of He^2+ molecular ion in a magnetic field for different quantum defects. The Fourier transform spectra of He^2+ molecular ion may be used to perform a direct comparison between peaks in the spectra and the scaled action values of closed orbits of the excited electron in external fields. We find that the spectral modulations can be analysed in terms of the scattering of the excited electron on the molecular core. Unlike the case of the Rydberg atom where the elastic scattering is predominant, modulations produced by inelastic scattering are also vital to the photoabsorption spectrum of the Rydberg molecule. Our results are in good agreement with the quantum results, which suggests that our method is correct. 相似文献
11.
12.
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. 相似文献
13.
Using closed orbit theory, we study the influence of the two parallel metal surfaces on the recurrence spectra of a hydrogen atom placed in the region between the two surfaces. The results show that the metal surfaces have significant effect on the photoabsorption process. Each resonance peak in the recurrence spectra is associated with one electronic closed orbit. In our work, we put the first metal surface at the critical value dc and vary the second metal surface. The results show that when the distances between the hydrogen atom and the two metal surfaces are close to the critical valuedc, the number of the closed orbits is the greatest and there are more peaks in the recurrence spectra. When the distance between the atom and the second metal surface is larger or smaller than dc, the number of the closed orbits decreases and there are fewer peaks in the recurrence spectra. The agreement between the semiclassical calculation spectra and the quantum calculation spectra suggests that our analysis is correct. 相似文献
14.
15.
16.
We analyze the spectra of simple Rydberg molecules in static fields within the framework of closed/periodic-orbit theories. We conclude that in addition to the usual classical orbits one must consider classically forbidden diffractive paths. Further, the molecule brings in a new type of "inelastic" diffractive trajectory in addition to the usual "elastic" diffractive orbits encountered in systems with point scatterers. The relative importance of inelastic versus elastic diffraction is quantified by merging the usual closed orbit theory framework with molecular quantum defect theory. 相似文献
17.
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. 相似文献
18.
19.
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
20.
We study periodic orbits of Hamiltonian differential systems with three degrees of freedom using the averaging theory. We have chosen the classical integrable Hamiltonian system with the Hooke potential and we study periodic orbits which bifurcate from the periodic orbits of the integrable system perturbed with a non-autonomous potential. 相似文献